Water Lilies

Water lilies – or Nymphaea, are considered by many to be the jewels of the pond. Not only are they beautiful to look at, but they also serve an important purpose in the pond, mainly in aiding its ecosystem. Water lilies spread across the water‘s surface, filling it with color and vibrancy all the while keeping the pond and the creatures in it safe and healthy.

Besides being pleasing to the eye, water lilies do a great deal to maintain the well-being of the ponds they inhabit. For one, they provide shade to keep the water temperature down during the hot summer months. By blocking out a lot of sunlight, the lilies help to keep the algae growth down. Their shade also gives shelter to any fish that may be in the pond ­– a respite from both the sun and any predators that may be lurking nearby. They also absorb nutrients in the water that would normally feed these undesirable green plants, keeping the water clear and clean-looking.

General Information

Hardy water lilies can remain in the pond year round. The Lily will die off in the winter time and produce new leaves and flowers in the spring. The hardy lily generally flowers from May through September. Flowers come in a variety of colors, opening in the early morning and closing in the late afternoon. Some hardy water lily flowers change color shades over the life of the bloom

Water lilies grow completely within water, with their blossoms flourishing on top of or above the water’s surface. They typically grow to suit the size of the area in which they are placed, spreading their leaves across the surface of the water and filling it with color.

Water lilies require a lot of sun to grow properly. In frost-free regions, they bloom all year. In cooler regions, they bloom during the summer and often into the fall. Throughout their growing season, they constantly generate leaf growth. These leaves live up to three or four weeks at the peak of the season.

The most striking feature of water lilies is the incredible amount of variation found among the different plants. From their shape and size, their color and fragrance, or their blooming patterns and growing periods, there is a water lily for every preference and every pond.

Water lilies range notably in size ­­– from miniature flowers with small leaves to giant plants that spread over 25 square feet. They come in a variety of shapes – star shaped, cup-shaped, pointed or fluffy, though that’s certainly not all. The leaves can be smooth or jagged, rounded or pointed.

The colors are just as varied, ranging from yellow, pink, red, white, purple, blue and orange. Several types of lilies are incredibly fragrant, as well.

 

Lily Flower Macro

In the center of all water, lilies are golden stamens – the organ of the flowers that bear pollen. When the lilies are young, the stamens stand straight. As the flowers age, they begin folding and curling into the flower.

The variations found in water lilies are especially pronounced when one breaks down the genus further, into hardy water lilies and tropical water lilies. They are similar, but they are not closely enough related to be naturally cross-bred. While both need a lot of sun to bloom and to thrive, tropical‘s, unlike hardies, can still bloom with as little as three hours of sun in a day. That said, tropical water lilies can be either day- or night-flowering plants, while hardies only open during the daylight hours. Tropical water lilies also start blooming later in the summer than hardies; however, they remain in bloom for longer than hardies. Tropicals also tend to have larger plants and larger blossoms than their hardy counterparts and tend to hold their blossoms higher above the water than do the hardies.

These are a few of the differences between the two types, but the list continues. Both subgenres – hardy water lilies and tropical water lilies – have their own characteristics and their own needs, as outlined below.

 

Hardy Water Lilies

Hardy Water Lily picture

The leaves of hardy plants are circular in shape with smooth, round edges. There is a waxy cuticle covering their surface. These features all aid in their survival: the shape helps to protect them from tearing in rough winds or waves, while the waxy cuticle allows the water to roll off the surface so that the leaves do not sink.

Hardies come in a variety of colors, ranging from red, salmon, pink, white, yellow, orange, peach and nearly black. There are some varieties– called changeable water lilies – that change their color over their bloom period (of three to four days). Hardy water lilies are the first of the lilies to come into bloom in the spring. Once the water temperature holds steady at 60 degrees, they will begin to bloom, spreading their pads across the pond with their blossoms eventually floating on or just above the water’s surface. These shallow-rooted plants need plenty of room to grow and spread up and out across the pond.

In the early spring, these fresh lily pads will begin to emerge on the water’s surface. Many of the lilies will be in bloom by mid- to late-spring. They bloom throughout the warm-weather months, eventually becoming dormant in the fall. These are perennial plants, meaning that as long as the rhizome – the underground stem that sends out roots and shoots – does not freeze, the plant will survive through the winter and bloom again in spring. Come winter, in areas with no frost, they will continue to grow, however, their growth will certainly slow down a bit. Year-round blooming is possible in frost-free zones. In areas with frost, however, the lilies survive through the winter only if they are below the pond ice.

These are not night-blooming flowers. Indeed, they are open in full bloom by mid-morning and are closed again by mid- to late-afternoon. Though each flower will last approximately three to five days, new flowers will constantly open throughout the season.

 

Tropical Water Lilies

Tropical Water Lily picture

The lily pads of the tropical plants come in different shapes, typically smooth, toothed or fluted. The edges are usually jagged and pointed and may even look ruffled. The pads are larger than the hardies, often taking up much more space in the water than they do.

A tropical’s blossoms are impressively sized – some span more than a foot across. Like the hardies, they come in many different colors. The two subgenres share the same color palette, for the most part (red, salmon, pink, white, yellow, orange, peach and near-black), but these types also come in blue and purple.

Though hardy water lilies are indeed very beautiful flowers, it is the tropical lilies that command – and capture – the most attention. They are larger and flashier than the hardies and tend to be more fragrant. They also tend to bloom for a month or two longer, stay open later in the day and are more likely than hardies to produce multiple flowers at any given time.

Tropicals require warmer temperatures than do the hardies to bloom, thus making them a bit more difficult to grow. After three or more weeks of temperatures above 80 degrees, these flowers will finally start to open up and bloom. Once they do, they fill the ponds with their colorful blossoms throughout the summer months and well into fall. After the hardies have gone dormant, tropicals will stay in bloom for several weeks longer, often until the first frost. During the winter months, however, they go dormant and die.

 

Tropical Lily Pads

There are two kinds of tropical water lilies: night bloomers and day bloomers. Lilies in the white, pink or red color range tend to be night bloomers, and these types are typically more fragrant. These flowers can take an entire hour to fully open, and tend to open in the late afternoon or early evening and close the following mid-morning.

Day bloomers, however, are the most common kind of tropical water lilies. They are fragrant, as well, but their scents are usually lighter and sweeter than the heavy-scented tropicals. Day bloomers have pointed petals and come in various shades, from magenta, red or pink, to white or yellow, or to blue or violet. They open mid-morning and close again during the late afternoon hours.

The blooms of both day and night bloomers open and close for periods of three to four days, holding their flowers above the water on strong, stiff stems.

 

Planting and Maintenance

There are two options when it comes to planting water lilies. They can either be planted in aquatic plant pots (the kind with no holes in the bottom) or directly in a hole created at the bottom of the pond. The planting of the lily itself will not be affected by the method you choose. Once you determine whether to use plant pots or plant pockets, you can begin the whole process.

With plant pots, a hole is created in the bottom of the pond into which the pots will be placed. These holes at the bottom of the pond must be able to accommodate the pot, so it is important that they are deep and wide enough. Once the vessel has been chosen and the lilies have been planted, you can place the pot into the hole. Take heed: the pot must lie directly on top of the soil at the bottom of the hole on level ground.

“If you choose to use the pocket method, you will plant the water lilies directly into the hole at the bottom of the pond.”

The size of your pond will determine the size of the container you use or the hole you dig. Again, lilies grow to suit the size of the area they are in – keep this in mind. As a rule, the larger the vessel, the larger the lilies will grow.

Water lilies thrive best in heavy garden topsoil but take care to make sure it has not been mixed with other substances such as manure or compost.
When determining where to place the water lilies, one must keep in mind that they do not thrive when faced with heavy water movement or with water splashing on them. Therefore, they should not be placed near waterfalls, streams or other such potential problem areas.

Maintaining the well-being of the lilies is vital for keeping ponds beautiful. Lilies should be fertilized regularly. This will help the flowers to grow larger and to bloom more frequently. You also must take care to remove all dead or yellowing leaves from the plant’s surface so they will not sink to the bottom and decompose. You should also keep the stems trimmed, pruning them as close to the rhizome as you are able.

There are some differences between hardies and tropicals, however, in terms of their planting and maintenance.

Hardies

Ideally, you should set your hardy lilies out once the early spring chill has subsided but before they begin growing. Doing so will enable them to produce blooms their first summer. If you buy the rhizomes before you can plant them, keep them submerged in water and leave them in a cool place and away from direct sunlight.

These lilies should be planted in pots or holes six to eight inches deep or in pots of a nine- to 20- (or more) quart capacity. The smallest pots recommended for standard and larger sized lilies are nine- to 10-quart containers. At least a five-quart container is recommended for the smaller lilies.

Fill the container about one-third of the way with topsoil then place the seed on top. Then cover the seed with soil so that the tip is just barely peeking through the soil. The blossoms of hardies will rise to the surface one at a time every three to seven days.

Maintenance is key, especially with hardies whose leaves continuously die and grow back throughout the growing season. Yellow leaves and four-day-old blossoms should be removed regularly. You should stop fertilizing hardy lilies in the early fall season as the growth of the plant slows. After the first frost, you should remove about two-thirds of the foliage.

Hardy lilies can live through the winter, but special care must be given to them during this time. In cold regions, they will survive if they are below the ice. If the pond isn’t deep enough to lower the containers as needed, remove the pans with the lilies in them and take them to a cool location. Keep them covered with damp material, such as a damp cloth, then seal them in a plastic bag to keep them from drying out.

In areas where frost does not threaten the growth of the lilies, their growth will slow down significantly but will, nonetheless, continue growing.

Tropicals

With tropical water lilies, planting should commence once the pond water has maintained a steady 69-degree temperature. It is very important to note that planting them before the water has reached this temperature may cause serious damage to the plants. They can go dormant – or, at worst, die. They must be planted immediately; unlike their hardy counterparts, these water lilies will not last more than a couple of days without the proper growing conditions.

These lilies should be planted in 15- to 20-quart tubs. They should be planted so that there are six to 18 inches of water growing over their tips.

They will begin growing roughly two weeks after they have been planted and then will begin blooming in another two to four weeks. They should be fertilized about twice a month.

In frost-free regions, tropicals will bloom year-round. In areas prone to frost, however, they do not fare the winter quite as the hardies do, and will die after a few bouts of frost. Many pond owners choose to replace them each spring. Keeping them alive is not a hopeless dream, however. There are options. Before the first frost, remove the plants from the water and trim back their foliage. Keep them in a greenhouse until winters’ end. They can be taken out once the water temperature has reached – and maintained – a steady 69 degrees again. They should be repotted in fresh soil and fertilized as usual. Once these steps have been taken, they can be placed back in the pond another season of growth and enjoyment.

Larkspur

Did you know? Larkspur is the flower of the month of July and its meaning denotes Fickleness.

Larkspur Flowers are irregularly shaped and bloom in a loose, vertical grouping along the upper end of the plant’s main stalk. Larkspur is actually a very complex flower consisting of both petals and sepals.

Kingdom
Plantae
Division
Magnoliophyta
Class
Magnoliopsida
Order
Ranunculales
Family
Ranunculaceae
Genus
Delphinium

Baker’s Larkspur (Delphinium bakeri) and Yellow Larkspur (D. luteum), native to some areas of California, are endangered species. Delphinium is a genus of about 250 species of annual, biennial or perennial flowering plants. The common name, shared with the closely related genus Consolida, is Larkspur.

Larkspur flowers come in a variety of colors including spikes of red, pink, violet and white. As a result of their generally similar floral structure, as well as the absence of genetic barriers to intercrossing, species of Larkspur are known to hybridize in many different combinations.

Facts About Larkspur

  • Larkspur, with tall spikes, makes excellent Cut flowers. Two varieties of Larkspur are ideal as cut flowers – Consolida ambigua and Consolida Orientalis.
  • The Larkspur Rose (Consolida ambigua) has tall spires of rose colored flowers. The 1/4 to 1/2 inch rose colored flowers are densely packed on tall stems.
  • The market for quality Larkspur is robust from many years. The alluring flower shape, a wide range of colors, and the appealing foliage combine to make Larkspur a popular, marketable cut flower.
  • Larkspur flowers tend to be fragile and relatively short-lived in the vase (under 7 days), making production for local markets more lucrative.
  • Larkspur grows to their full potential in climates with cool, moist summers.
  • The Larkspur plant is toxic. The stem and seeds contain alkaloids.
  • Apparently, domestic sheep are not affected by the toxins in Larkspurs. So, sometimes sheep are used to help eradicate the plant on cattle range.
  • Larkspur looks identical to perennial Delphiniums.

Growing Larkspur

  • Sow Larkspur seeds directly in the garden in the spring.
  • Sow them in the location you want them to grow as Larkspurs do not like to be transplanted.
  • Larkspur plants should be spaced about 6 to 8 inches apart.
  • Level with the soil surface. Carefully fill in and firm the soil gently.
  • Water the Larkspurs deeply to encourage root development, but be sure the roots do not stand in water or they will be at risk for root rot.

Larkspur plant care

  • Larkspurs are best started from seed in spring or fall.
  • Apply a thin layer of compost each spring, followed by a 2-inch layer of mulch to retain moisture and control weeds on Larkspur beds.
  • Water Larkspur plants during the summer if rainfall is less than 1 inch per week.
  • Soil should never dry out for the Larkspurs.
  • Stake tall varieties of Larkspur to prevent hollow flower stalks from snapping in the wind, and deadhead after flowering to encourage rebloom.
  • After the first killing frost, cut the Larkspur’s stems back to an inch or two above the soil line.
  • Divide plants every three to four years as new growth begins in the spring, lifting plants and dividing them into clumps.
  • Remove spent Larkspur flowers as needed. Trim back to the ground in late fall after the foliage dies back.

Container Planting: Replace High-Maintenance Annuals With Succulents – DIY – Heirloom Gardener

By switching out flowers for the unique colors and shapes of succulents, you’ll add an unexpected, yet attractive element to the design of your garden. Succulents are taking the garden world by storm, with countless new varieties available at your local nursery. Besides being a trendsetter in your neighborhood, you’ll have much less to do to maintain your garden containers when you make the switch. As opposed to flowering annuals, succulents require much less water, need infrequent applications of fertilizer, and do not need to be replaced annually.Tired of caring for high-maintenance flowering annuals in pots? Replace them with succulents, which add unique beauty at a fraction of the water and maintenance.

Source: Container Planting: Replace High-Maintenance Annuals With Succulents – DIY – Heirloom Gardener

Botany of Hibiscus: Plant Immune Systems

Do Plants Have an Immune System?

What Do we Know about Plant Immune Systems?

Yes. That much we do know! Their immune system is commonly considered to be passive or innate. This means that unlike animals, plant immune systems don’t send specialized immune cells through a bloodstream to all parts of the plant where they can aggressively recognize and fight off specific invaders. But honestly, we still know very, very little about plant immune systems. Every few years a new study comes out with the amazing news that plant immune systems do wild and weird things that we never thought they could do. So the best we can say at this point is that we still have a LOT to learn about plant immune systems. We may well find a whole world of new information about immunity once we can truly understand how plants fight disease.


‘Scarlet Beauty’

We know how to eliminate external pests and bugs, and we’re pretty good at fighting many kinds of fungal infections. We’ve written many, many articles on these topics and have many pages of our website devoted to them. But what about plants that are infected with bacteria and viruses? Many gardeners and most farmers won’t even try to cure plants with viral or bacterial infections. Modern science recommends that plants with these kinds of infections be thrown in the garbage as soon as the illness is discovered. That’s all well and good for some of our more common garden variety plants! But what about our cherished hibiscus and rarer plants? For those of us more tender-hearted gardeners who get deeply attached to our plants, isn’t there some way to try to cure a sick plant?

We’re sad to say that we don’t yet have the answers to that question. We’re still working on it ourselves! But we thought our readers might like to hear some of the lines of inquiry that we’re looking into, some of the newest research, and some ideas of things we are trying out on our own plants.

A Healthy Plant + Good Hygiene = Better Immunity


‘Thanksgiving’

The best defense against any invading microbe, as you’ve heard many times before, is a healthy plant. Healthy plants have strong cell walls that keep out almost all diseases very effectively. The problem comes when a cell wall is broken into by some contaminated outside entity, such as biting insects carrying disease, or dirty human pruning shears. Those are probably the two most common ways that plant diseases are spread from one plant to another. Once a single cell wall is breached and infection is planted in that one cell, the disease can begin in the plant. A healthy plant even then will be able to wall off that one cell, flood it with protective chemicals, and prevent the disease from spreading. But if the insects or pruning shears cut through cell walls all over the plant, and many cells become infected, the plant has much less able to fight off the infection.


‘Lemon Kiss’

We’ve all seen this happen. Our hibiscus plant gets a case of spider mites that we don’t catch and cure immediately. The plant loses a lot of leaves, and even though we get rid of every last bug, the hibiscus just continues to go downhill. It grows baby leaves, but they look weird, turn brownish or yellowish or look deformed, and they fall off before they get to normal size. The plant keeps trying to grow new baby leaves everywhere, but they all go through this slow death. The plant may linger for months, or sometimes even years, in this state, and then finally some last straw kills it – a cold snap, a hot spell, too much or too little water, almost any stressor. This is a classic case of insects carrying infection into plant cells and infecting it so badly that the plant cannot recover. It’s one of the saddest things we see in hibiscus because the plant stays in that sickly state for so long, and yet we still can’t save it. Or can we?

What Might Work to Help a Plant Fight Disease?

But maybe we can start saving these plants! All hope is not lost. Here are some ideas suggested by new scientific research into plant immune systems. At HVH we are trying as many of them as we can, but we welcome any and all information from other hibiscus lovers on what has worked on not working for your hibiscus.

A Growth Enhancer ~ The First line of Defense for Sick Plants


‘Joy’

The first line of defense is to pump your plant full of as many health-supporting nutrients as possible. Remember, good health alone will help your plant fight off disease all by itself. So as quickly as you spot any signs of stress, pump up your plant’s nutrition, and fill it full of the hormones and building blocks that will help it pull itself through the disease. A good growth enhancer product will do this very quickly. We have saved more sick hibiscus with this product alone than everything else we have tried all together. If there is only one product you keep on your shelf for emergencies, it should be a growth enhancer.

Vitamins ~ The Research Cutting Edge


‘Crystal Pink’

Most vitamins and many substances that we use for medicines are derived from plants where they grow naturally. Although we harvest these substances, analyze them, and recreate them for human and animal health purposes, we rarely stop to think about what purpose these substances serve within the plants they naturally occur in. The newest research is suggesting and confirming the suggestions that these substances serve healing purposes for the plants that produce them. There is not very much research yet in this area, but what there is is beginning to show promise. Here is a quick look at some of the findings.

    • Vitamin D

      Several studies have found that Vitamin D watered into the soil promotes both increased root growth and increased plant growth in plants. One study thought this was possibly due to vitamin D’s effect on increasing calcium absorption in plants, just as it does in animals. But with or without added calcium, vitamin D has had a positive effect on boosting the growth and healing of stressed plants.

 

    • Vitamin C

      There have been mixed results with Vitamin C. Some plants have shown increased growth and ability to fight off bacterial disease with Vitamin C added to the soil or water. Other studies showed no improvement. All plants make their own vitamin C, so scientists hypothesize that if a plant has been able to make enough vitamin C on its own, extra vitamin C won’t help it. But if it has been too sick to make enough of its own, the extra vitamin C will help. Until recently we didn’t even know for sure if all the vitamin C plants make actually did anything useful for them. But a 2009 study from Cornell University proved that one plant species at least can’t survive without vitamin C, that it was essential for photosynthesis, and that vitamin C was highly protective against several types of stressors, including air pollution, ozone, and ultraviolet radiation. The plants that didn’t have any vitamin C grew “shriveled leaves.” Other studies of other plant species have also shown that vitamin C is essential for growth and has a protective effect on plants that are under different kinds of stress, such as drought.

 

    • B Vitamins

      B vitamins have been known to help plants resist disease for many years. More recent research confirms those earlier findings. One treatment of B vitamins has been shown to increase resistance to bacterial, viral, and fungal diseases for more than 2 weeks. All of the B vitamins researched so far seem to have a similar effect in studies on many different types of plants.

 

    • Aspirin

      Amazingly, aspirin seems to be involved in plant immune activities at almost every level in almost every plant studied. It seems to be the near-universal plant cure-all, just as it was the near-universal human cure-all for centuries of medical history. But in plants aspirin does more than just alleviate pain. It actually blocks microbes and fights off bacterial, viral, and fungal disease. This immunity comes at a cost though. But it weakens a plant to have to make its own aspirin, and it makes the plant more vulnerable to insect attacks. This is one of the reasons that sick plants often seem to get better, then go downhill and get sicker than ever. The act of fighting off disease is very hard on plants, and the damage that follows the immune reaction may be worse than the original disease. This is why extra nutrition of every kind is so important for sick plants! They need all the help they can get when disease strikes.

 


‘Mother Nature’
    • No matter what you try, remember, the number one rule for sick or stressed plants is always WARMTH. Keep your plants as warm and toasty as you can, even if you need to reduce their light!

 

  • Cipollini, D., and Heil, M., 2010. “Costs and benefits of induced resistance to pathogens and herbivores in plants.” CAB Reviews: Perspectives in Agriculture, Veterinary Science, Nutrition and Natural Resources.

 

 

 

 

  • Smirnoff, N., Dowdle, J., Ishikawa, T., 2007. “The role of VTC2 in vitamin C biosynthesis in Arabidopsis thaliana.” Comp Biochem Phys A, 146(4), S250-S250.

 

 

 

 

  • Li, S., Xue, L., Xu, S., Feng, H., and An, L., 2009. “Mediators, genes and signaling in adventitious rooting” The Botanical Review, 75:2, 230-247.

 

 

Botany of Hibiscus: Potassium

Many of us have learned from experience that giving our plants more potassium makes them more colorful in every way – darker green leaves as well as bigger and more colorful flowers. The skeptical types among us ask if this is just our imagination, or is it really true? Some of us have tried growing plants side-by-side with and without extra potassium to see the difference, and amazingly the difference is visible. But fertilizers with high enough levels of potassium are still so hard to find! So how can it possibly be true that higher levels of potassium are better for plants? Our plants look better with extra potassium, but are they actually healthier, or is it just a gardener’s illusion?


‘Hot Buttered Rum’

The short answer is yes, they are actually healthier with more potassium. When leaves are greener, it means they have more chlorophyll, better hydration, more photosynthesis, more protein, and more sugar to support the plant. Bigger and more colorful flowers are a symptom of good health, just as bigger, better-looking fruits are a symptom of better health in food crops. Higher doses of potassium produce not only more attractive and cosmetically beautiful plants. They also produce healthier, more vigorous plants.

How Does Potassium Work?

The mystery of potassium is that plant cells are not actually made of potassium. It’s not used in the molecules that make up leaves, chlorophyll, stems or flowers. And yet, plants go downhill and die if they don’t get enough of it. What does potassium do that is so important for plants?

Molecules ~ The Factory Raw Materials


‘Dynamo’

Think of a plant like a factory full of parts that will eventually go together to make something. The parts are the molecules that make up the plant. These parts, the molecules, go together to make leaves, stems, flowers, roots, every part of the plant. More molecules make up the nutrients that feed the plant, water, air, fertilizers, nutrients from the soil, etc. All these parts are vital to the plant, of course! But without workers and machines to put them together, they are just separate, loose parts. How do these molecules get put together to make a plant grow and bloom?

Enzymes ~ The Factory Machines

The machines that put the molecules together are called enzymes. We think of enzymes as chemicals in our stomach that help us break food apart, but enzymes all through nature serve many different purposes, both for building and for taking apart. Plant enzymes are no different. They are like little chemical cogs that grab onto molecules, put them together, take them apart, or both. These enzymes are all through every part of a plant, from root tips to flower tips, working like little machines to do all the things that plants need to do throughout their lives. But these machines don’t work on their own. Something needs to make them start and stop. Something needs to move the molecule parts to where the machines are, connect them up, and turn the little enzyme machines on and off. How does this happen? What makes it all start working?

Potassium ~ The Factory Workers


‘Daisy Mae’

Potassium! Potassium is like busy workers all through the factory. It is everywhere in the plant, all through every part of the plant. It turns the enzyme machines on and off so they can turn molecules into cells, food, leaves, stems, roots, flowers and everything else that makes up a plant. Tiny potassium ions shape the molecules and enzymes so that they fit together, like cogs and gears that have to fit together perfectly to make the machinery work. Without potassium, nothing fits together and the machinery doesn’t get turned off and on.

Potassium’s worker role is important in other ways too. It moves water all through plants, and along with the water, it moves nitrogen, phosphorus, trace minerals and nutrients – all the nutrients in the fertilizer we feed our plants, and all the goodies it picks up from the air, water, and soil. It turns out that almost everything that needs to travel through a plant is moved by potassium. Water is the conveyer belt and potassium makes it all move along exactly where it’s supposed to go.

Too Little Potassium ~ The Factory Shuts Down


‘Sizzle’

No wonder potassium is so important! Without potassium, everything shuts down in a plant. Think of a factory when all the workers go on strike when machines sit idle, and parts gather dust and rust when raw goods don’t get carried to conveyor belts when production lines stop and nothing new is made. This is a plant without adequate potassium. It can’t grow new cells. It can’t use sun and carbon dioxide to build sugars for food. It can’t repair injuries. It can’t make new chlorophyll or leaves. It can’t get nutrients where they need to go. Flowers get smaller and duller until they finally disappear. Leaves get paler and smaller. The oldest leaves start to lose their chlorophyll and turn yellow and brown, as the plant tries to save the youngest leaves in the growing tips. Finally, the whole plant turns yellow, brown, and shriveled and will eventually die if the potassium deficiency continues. It doesn’t matter how much nitrogen, phosphorus, trace minerals, water, and the sun are there. Without potassium to turn the enzymes off and on, and to transport the goodies all through the plant, the factory can’t function. The plant can’t function. It all grinds to a halt.


‘Caribbean Beauty’

We have experienced this firsthand in our early days with hibiscus before we discovered just how much potassium our plants needed. A lot of trial and error and listening to the wrong “professional” advice gave us very bad results at times until we learned to just ignore everything we heard and follow what actually worked. In those days we didn’t understand how or why potassium worked. We just knew that it did, that it was necessary, and that our hibiscus needed a lot more of it than anyone else seemed to think they should. Now, thanks to research in crop areas like wine grapes and legumes, as well as flowers, our understanding of how potassium works are growing every year, and we no longer feel like lone renegades with our constant advice to hibiscus lovers to use more potassium.

Of course, the role of potassium in plant health is more complex than this, and probably much more complex than science even knows right now. But a basic understanding helps us make better decisions about how to care for our hibiscus, and our other plants as well. Plus, as every kid will tell you, a little bit of science is always fun!

 

 

  • Better Crops, 1998. “Functions of Potassium in Plants.” Vol 8, No. 3.

 

  • Broschat, T., 2008, reviewed 2011. “Nutrient Deficiency Symptoms of Woody Ornamental Plants in South Florida.” Institute of Food and Agricultural Sciences, University of Florida, http://edis.ifas.ufl.edu/ep362.

 

  • Delgado, R., González, M., Martín, P., 2006. “Interaction Effects of Nitrogen and Potassium Fertilization on Anthocyanin Composition and Chromatic Features of Tempranillo Grapes.” International Journal of Vine and Wine Science, 40(3), 141-150.

 

 

  • Pal, P., Ghosh, P., 2010. “Effect of different sources and levels of potassium on growth, flowering, and yield of African marigold (Tagetes erecta Linn.) cv. ‘Siracole’.” Indian Journal of Natural Products and Resources, 1(3), 371-375.

 

 

  • Silberbush, M., Lieth, J.H., 2004. “Nitrate and potassium uptake by greenhouse roses (Rosa hybrida) along successive flower-cut cycles: a model and its calibration.” Scientia Horticulturae, 101, 127–141.

 

 

Botany of Hibiscus: Chlorophyll

Chlorophyll in plants is that amazing green substance that turns water, air, and sunlight into food. Most of us (at least most mothers!) at some time or another, while cooking yet another dinner for our human offspring, find ourselves wishing that we humans could just produce chlorophyll in our bodies to make our own food so we wouldn’t have to spend so many hours of every day in the tedious process of providing food for our families. But strangely enough, we do have a substance very similar to chlorophyll in our human bodies – hemoglobin! Yes, the stuff in our blood that makes it red, the important part of our blood that picks up oxygen and carries it to every cell in our body, is very similar to chlorophyll. The molecules are the same special type of chemical ring, only chlorophyll has green magnesium in the center and hemoglobin has red iron in the center. Unfortunately for us though, our red molecules don’t turn air, water, and sunlight into food!


Chlorophyll Molecule
Magnesium in the Center

Still, it does help to realize that chlorophyll is as important for plant life as red blood cells are to animal life. A chlorotic plant that has too little magnesium to produce chlorophyll feels about as sick as an anemic animal that has too little iron to make red blood cells. Anemia and chlorosis have much in common. In both states, the plant or animal can keep dragging along, and a mild case at least won’t kill them. But an anemic animal and a chlorotic plant won’t thrive either! So if you keep your hibiscus plant blooming and blooming, but don’t stop to notice sickly yellow leaves, you could be working your plant into a state of very poor health.


Hemoglobin Molecule
Iron in the Center

Chlorosis, like anemia, is easily remedied with good nutrition. Part of good nutrition for plants is the sun since they use sunlight to produce their own food. So during the winter months when your hibiscus may be getting a lot less sunlight, it’s important to make sure you keep the levels of nutrition up – particularly the nutrients involved in producing chlorophyll: magnesium, iron, and nitrogen. Instead of stopping all fertilizing in the winter, just cut down your fertilizing a little bit, but make sure you don’t starve your hibiscus by giving them no fertilizer at all. We would never consider stopping all nutrition for our children or our animals in the winter, or stopping their vitamins, or allowing them to eat only junk food. Plants are not as different from animals as we might think.

How does Chlorophyll Work?


Chlorophyll from a
hibiscus leaf starts
off bright green

In its most simplified explanation, when sunlight hits a chlorophyll molecule, electrons on the molecule get excited and start to move. Those jumping electrons cause electrons on the next chlorophyll molecule to move, and the movement, or energy, is passed from one molecule to another until it is used to build glucose, the primary food of both plants and animals. This process, photosynthesis, goes on continually with all chlorophyll molecules in contact with sunlight all through the daylight hours. Then, just as animals move glucose through blood to all cells in the body, plants move glucose through their sap to all cells within the plant.


Under a bright light
chlorophyll glows red
as the electrons get
excited & move

So how do we help our plants continue to make glucose in the low-light conditions of winter? There are two ways to produce more glucose in plants – one is to provide more light, and the other is to provide more chlorophyll. An increase in either light or chlorophyll will increase glucose production. So in the dark days of winter, providing more of the building blocks of glucose – lots of magnesium, iron, plant hormones, and nitrogen – will help the plant make more chlorophyll and maximize use of the small amounts of light available. In other words, when there is less sunlight available, providing chlorophyll-building nutrition becomes MORE important, not less important.

Botany of Hibiscus: The Roots

All of us spend a lot of time looking at our hibiscus flowers, and many of us are careful about inspecting the leaves and branches. But how many of us pay much attention to the roots? The sad fact is, when a hibiscus plant dies, most of the time it is because of root problems, and most root problems are either indirectly or directly caused by improper watering. So if we want to keep our hibiscus healthy and blooming, it is very important to have at least some knowledge of how roots work.

It helps to think of a plant as a giant soda straw. The sun effectively sucks on the straw by evaporating water out of the leaves – what we call transpiration. On a cold or cloudy day, the sun draws less water out of the leaves, so less water is sucked up through the straw.

The part of roots that we are most familiar with are the big, crisp, tough branch-like roots. These are filled with a spongy center of dead cells, called the xylem that functions like the hole in a straw, where water moves up through the plant as the sun sucks it out the leaves. The xylem is tough and turns woody to help support the plant and to provide a rigid straw that does not collapse with strong sucking action. Because the xylem is made of dead cells, it does not use up any of the water and nutrition that passes through it. It very efficiently functions as a non-living tube that transports all its goodies up to the above-ground parts of the plant. It is a one-way tube, that moves water only upward, and it only works when the suction of the sun is pulling the water up. The xylem has no way to push water up or to help in the transport process. It is just a straw, non-living, non-active.


Cross Section of a Hibiscus Root

Surrounding the xylem are living cells, called “phloem” that are capable of actively pushing nutrients both up and down the plant. These cells push and pull sugars and proteins from the leaves down to the root cells and to all other parts of the plant to nourish them. Roots have a lot of hard growing work to do, pushing down into the hard and rocky soil, growing through every kind of obstacle, creating new cells just as much as the top part of the plant does. The phloem brings the growing root cells the food and energy for all this hard work.

But the most important part of the root is still to be seen. The very bottom of the straw where the water and nutrients come into the plant is not these big parts of the roots that we see when we dig up a plant. The bottom holes in the straw are all the little tiny, thin, fine, delicate root hairs that we barely notice on the roots. Root hairs have very special cells that stretch out like little tiny absorbent wicks to soak up water and nutrients from the soil. They are very active cells, more active than all the other root cells, to actively, quickly, and efficiently move water and nutrients into the main part of the roots. When we transplant plants, we tend to be careful with the tough, visible parts of the roots, but we often do not notice the soft, tiny root hairs, which are actually the most important parts of the root. If we crush or destroy these tiny root hairs in our transplanting, the plant will experience much more “transplant shock.” If we are very gentle and careful not to crush them or knock them off and spread them gently into soft, fluffy soil, the plant will survive the transplant with much less suffering.


Healthy roots need air & oxygen
in fluffy soil that drains well.

Roots Need Oxygen!

We know that roots need water, of course. But the less obvious thing that roots cannot live without is air – oxygen to be exact. Yes, just like us, they need to be able to breathe oxygen down there in that dark, damp soil. The phloem sends them sugars and proteins, but they need oxygen to turn this food into energy for growing and working. We forget how hard roots have to work, how much energy it takes, and how much oxygen it takes to burn food for energy. The green parts of plants can make their own oxygen through photosynthesis. But the roots have no green chlorophyll and no light. They can’t photosynthesize, and they can’t make their own oxygen. The only way they can get oxygen is to get it out of the soil.

Helping Roots Get Oxygen

Prepare the Soil: So how do we help our hibiscus roots get the oxygen they need? Before we plant, we fluff up the soil, dig it up, break it up, and put things like coco coir into it to make it light and fluffy and full of air pockets.

Check for Drainage: Next, we check our hole or pot to make sure it drains properly by filling it with water and watching to see that the water drains out quickly. If water sits in our hole or pot for more than 24 hours, the plant will be starved of oxygen, and “drown” just like we would. When a plant drowns, it is a very sudden death. One day the plant will be healthy and green, the next day it will be completely dead. Nothing will bring it back. As for all living things, drowning is fast and fatal for plants.

Use Proper Watering Techniques: From this point on, the way we water determines how much air stays in the soil. We all know that too little water will dry the plant out and kill it from thirst, so we are very careful not to underwater. But the most common cause of plant deaths is overwatering by flooding the soil too quickly. Flooding the soil with water that doesn’t drain away quickly, drives all air pockets out of the soil. In order to understand this, we need to learn a little bit more.

Why do Plants Wilt?

Wilting is simple. It just means that the sun is sucking water out of the leaves faster than the roots are able to fill the straw and send water up. Wilting means that water is not able to pass through the roots and up to the plant for some reason – there’s no water in the straw. Many things can cause this problem though, and it’s not always obvious what the cause is.

Drought and Flooding: The most obvious reason for a wilted plant is drought. You forgot to water it, the soil got too dry, and there’s no water for the roots to absorb. We all do this at times, and of course, there’s an easy fix! We just need to water the plant. BUT…. at this point, we need to be very, very careful. A plant that has dried out to the point of wilting has dried its roots out as well as it’s top, green growth. When roots dry out, the tiny root hairs die very quickly and easily. Remember! Those little root hairs are the end of the straw that suck up the water. If many of them have died, the plant will not be able to suck up very much water! So after you have let a plant wilt from drying out too much, water very gingerly, and do not let the plant stay in standing water at all. Make sure all excess water runs out quickly. It is very easy to flood the remaining root hairs and drown the plant at this point. This is one of the biggest mistakes that all of us make at some time in our lives. We feel so guilty for letting our poor baby dry out to the point of wilting that we give it a HUGE drink of water that it never recovers from.


Early stages of root disease:
Plant is starting to wilt, leaves look yellowish,
The plant doesn’t look quite right.

Overwatering: Overwatering is like very slowly drowning a plant, bit by bit, day by day. When you overwater a hibiscus, the soil stays very wet, loses all its fluffiness, and begins to close up all the little air spaces that roots use to get oxygen. Over time, the soil gets more and more compacted until there are almost no air spaces left at all, and the plant finally dies of drowning. But in the early stages of overwatering, your plant will just look a teeny bit wilted and stressed. The leaves will be a bit off-color, and you’ll notice that something is not quite right. If you catch your mistake early, poke some holes in the soil and fluff it up a little bit to get some air into it, then reduce your watering or improve your drainage, you can save your plant. You will need to be very patient as the plant regrows the roots that have been damaged due to a lack of oxygen, but with time and patience, the plant can recover.

Root Diseases: Root diseases are a common cause of plant wilting and death. Sick roots stop working properly, which means they can’t take in water, and the plant dries out and dies, no matter how wet the soil is. A very common cause of root disease is fungi that can occur naturally in garden soil. Some fungi make a hole in the plants outer skin and enter through that hole. Other fungi enter the plant through the breathing holes in the skin, called stomata. Then they fill up the spaces that water is supposed to move through and steal the plant’s nutrition. Or they exude toxins that kill the cells that water is supposed to move through, and then move in and eat those cells. Either way, the fungi fill up the “straw” and block the flow of water up to the plant. Our poor hibiscus plant slowly dies of a lack of water.

Fungal infections are nearly impossible to cure; it is much better to use good prevention techniques. A healthy hibiscus in healthy soil can usually fend off fungal attacks. But a hibiscus that sits in the soggy soil becomes weakened and loses its natural defenses. The roots are already damaged by the soggy conditions, and the fungus is able to invade them easily. Strong and healthy roots are much harder for fungi to enter.


The black tip on the center root is the start of a Fusarium infection
The roots are both sides are completely black & fully infected.
Courtesy of The Korean Society of Mycology

In order to prevent poor soil conditions that weaken roots, try to keep the crown, the point where the roots meet the trunk, of your hibiscus as dry as possible. This is especially important in very wet, cool, or humid climates or growing conditions. Plant your hibiscus so that the crown is slightly above the ground, and try not to water directly onto the crown. Try to get plenty of air and sunlight down onto the crown too so that it dries out during the daylight hours. But most important, make sure your soil drains well and quickly. Roots that sit in water for long hours every day are sitting ducks for fungal infections.

If you live in an area that gets a lot of rainfall and you can’t avoid wet soil for your plants, you may want to plant your hibiscus in raised beds or in pots that you raise up off the ground onto a deck or pallet. Finding a way to provide optimum drainage is key to preventing root diseases and to keeping your hibiscus roots healthy and vigorous.

 

 

 

  • The Korean Society of Mycology, 2014. “Phytophthora Root Rot and its Control on Established Woody Ornamentals.” Mycobiology. Mar 2014; 42(1): 66-72. Published online Mar 31, 2014. doi: 10.5941/MYCO.2014.42.1.66

 

 

 

  • Smith, K. L. “Root Problems on Plants in the Garden and Landscape.” Ohio State University Extension,HYG-3061-96, http://edis.ifas.ufl.edu/ep362.

 

 

 

 

History of Hibiscus

The ancestors of today’s modern hibiscus hybrids were sprinkled all around the globe, following the Equator from one warm, tropical land to the next. The eight hibiscus species that are considered to be the ancestors of the modern exotic hibiscus were originally native to Mauritius, Madagascar, Fiji, Hawaii, and either China or India.

Similar in many ways to today’s hibiscus, the ancestors were characterized by free flowering, tall and willowy bushes (mostly), and the ability to form seeds using their own pollen that would grow into plants that are genetically identical to the parent plants. The flowers were smaller than many of today’s hibiscus, but they made an abundance of these smaller, single-colored blooms.

Why are these hibiscus species considered ancestral to the modern varieties and not others of the hundreds of known hibiscus species?

These eight hibiscus species have all been involved in the development of the modern hybrids that we are familiar with today. That means that they have proven to be cross-compatible with at least one other of these ancestral species. In other words, applying the pollen of one of these species to the staminal pads of another of these species will result in seeds that are viable. Most hibiscus species are not genetically compatible with each other and cannot reproduce with each other, but these eight can do so and have been so used over the last 300 years.

Do the ancestors still exist, and can we find them to grow?

Yes, most of the ancestors do still exist. Here is a quick rundown on them and their availability today:


‘Hibiscus Rosa-Sinensis’

Hibiscus Rosa-Sinensis: This one is a little confusing because you will often see the entire group of ornamental, tropical hibiscus that is so common in the southern US referred to as named varieties of Hibiscus Rosa-Sinensis. This is not entirely accurate, as ornamental hibiscus is really all hybrid crosses of any of these eight original native species hibiscus. So even though modern hibiscus are all called varieties of Hibiscus Rosa-Sinensis, the truth is that they’re all a mix of several species. But Hibiscus Rosa-Sinensis is actually the correct name of one of the original species plants.

Hibiscus Rosa-Sinensis was first discovered in China or perhaps India. Botanists are not really certain since no wild stands of Hibiscus Rosa-Sinensis have been found growing anywhere. Wherever it originated, it was brought back to Europe by explorers in the 1700s. Carl Linnaeus, who gave us the Latin-based taxonomy of plants that became the standard, collected at least one specimen of Hibiscus Rosa-Sinensis and gave it that name in 1753 when he released his famous books, “Species Plantarum” (Species of Plants). He described a red double flower in that first naming of hibiscus.

This species, Hibiscus Rosa-Sinensis, has been grown ever since in European botanical gardens and by private collectors. HVH obtained it from Europe a few years ago and now offers it in our online store. It is a beautiful, vigorous, glossy-leafed plant with intensely bright red, double flowers. It is very fun and easy to grow, even as a houseplant, and it is definitely recommended for modern hibiscus lovers.


‘Hibiscus liliiflorus’

Hibiscus lilliflorus: This species of hibiscus is native to the Mascarene Islands off the east coast of Africa. One of these islands, Mauritius, has been an important seaport for centuries. Back in the 1700s and 1800s, it was a major stopping point for ships sailing around the southern tip of Africa on their way to or from India and China. Mauritius was controlled by several European countries at different times in its history, but during the English rule in the 1800s, it was discovered that Hibiscus lilliflorus, native to Mauritius, could be cross-pollinated with Hibiscus Rosa-Sinensis and new, fertile hybrids would result.

Hibiscus lilliflorus still exists in Mauritius and is grown in many botanical gardens around the world. HVH collected this species from the Quail Botanical Gardens in Encinitas, California, and now offers Hibiscus lilliflorus plants in our Online Store. It is a tall, slender plant, and a vigorous grower. The flowers are 3-4″ flute-shaped singles that are produced freely and in abundance. Easy to grow, we highly recommend this ancestral species for anyone interested in hibiscus.


‘Hibiscus schizopetalus’

Hibiscus schizopetalus: This species was discovered in Madagascar, a large island located between Mauritius and the east coast of Africa. Since its discovery, the unique flowers have caused this species to become highly desired by plant collectors, and it is now found in private and public gardens around the world. Schizopetalus means “split petals” and describes the unique and delicate look of the flowers of this hibiscus.

Hibiscus schizopetalus is spread mostly by vegetative propagation, and HVH now offers plants of it from our online store. It grows tall and lanky with medium vigor, and the charming flowers appear on every stem once it matures. The most unusual of all the hibiscus species, Hibiscus schizopetalus is a worthy addition to any hibiscus collection.


‘Hibiscus fragilis’

Hibiscus fragilis: This species was also discovered on the island of Mauritius, but is almost extinct in the wild. Only a few dozen plants of it are known to still be growing on the island, but botanical gardens such as the Kew Gardens in England have made efforts to save it from extinction.

HVH has obtained seeds of Hibiscus fragilis and plans to offer this rare species starting in 2010. The flowers are red singles, and the bush seems so far to be slow growing and sturdy. We will have more to say about this endangered species as our own plants of it grow and mature.


‘Hibiscus Genevieve’

Hibiscus Genevieve: This is the third species of hibiscus to be discovered on Mauritius. It is said to have pink single flowers, but we have so far been unable to obtain seeds of a plant of this species. If we do we will have more to say about it.


‘Hibiscus arnottianus’

Hibiscus arnottianus: This species was discovered all the way around the world from Africa, growing on the Hawaiian Islands. The flowers are white, and the bush is well branched though less tall and upright than the African hibiscus species. Once Hibiscus arnottianus was spread among the various islands, the species formed various sub-species as they evolved on the separate islands. These sub-species, though very similar, vary slightly one from the other. Today it is rather difficult to determine if one has a particular sub-species, so many are collected, traded or sold as Hibiscus arnottianus without making the distinction.

Hibiscus storckii: This species was discovered and named by a botanist visiting the island of Fiji back in the 1800s. Expeditions to the island since then have not located any surviving examples of this species of hibiscus still growing on Fiji. The flowers are light pink, and the bush is said to be small with cascading branches. Kew Botanical Gardens in England received cuttings of this species directly from the botanist who discovered it and fortunately has been able to grow it continually ever since.

Hibiscus kokio: This species is another that was discovered growing in the Hawaiian Islands. It is a smaller, less vigorous hibiscus, making small red flowers. We doubt that this species has played much of a role in the development of the modern ornamental hibiscus, but are still researching this question.

hibiscus mapWhy should I bother collecting and growing the ancestral species?

Several reasons, in our opinion. First, they are great plants that bloom more freely than most of the modern exotic varieties. Second, it is fascinating to possess and grow historically important plants. Once you do, you can see where various traits in modern varieties likely came from. You can also use the ancestors as part of a hybridizing program to infuse vigor and ease of propagation back into a line of modern varieties. And lastly, by growing these original species plants, you are helping to keep them safe from extinction. None have secure native environments to thrive in, and some are extinct except for the specimens grown in human planted gardens. These eight species of hibiscus found all around the world are genetically related enough to be able to successfully cross-pollinate each other. In other words, any of these eight species can serve as mother or father (seed maker or pollen donor) and viable seeds that will germinate and grow as hybrids will result from this cross-pollination. Take a look at at the world map above – isn’t it fascinating that these eight genetically related species were originally found so widely separated around the world?

Where did the hybridizing begin?

 


The Original H. Rosa-Sinensis
Collected & Named by Carl Linnaeus
Courtesy of the Linnaean Society of London

We don’t know how the original 8 species of hibiscus came to be separated from each other. We can speculate that at one time they grew closer together but that continental drift eventually separated them. Or, it is possible that they all come from the same ancestral hibiscus and that this ancestral plant evolved into the different but related species once stands of this ancestral species were separated from each other. We can see this happening even now in the Hawaiian islands when plants of one of the Hawaiian native hibiscus species develop unique characteristics as they grow and evolve on separate islands. Another theory worthy of consideration is that in pre-historic times the ancestors of the Polynesian people set out from their original home in southeast Asia and migrated throughout the Pacific, carrying with them seeds of the original hibiscus species that they planted in various locations during this long migration. However it happened, by the year 1700, eight cross-compatible hibiscus species were growing naturally on tropical islands off the east coast of Africa and all the way to Hawaii.

hibiscus map

Take another look at the map. The island location of the original species played a critical role in what happened next. By the 1700’s, when Carl Linnaeus named one of the species Hibiscus Rosa-Sinensis, European exploration of the world by ship was well underway. Many ships sailed with botanists and zoologists, whose job it was to discover new and commercially important species of plants and animals. Many ships were engaged in trade with the Far East, and the most common route between Europe and China was around the southern tip of Africa. As the map shows, the islands of Mauritius and Madagascar lie along this trade route. Both islands were used as important ports where ships would stop to resupply for the journey ahead.


Original Description of H. Rosa-Sinensis by Carl Linnaeus
in Species plantarum, exhibentes plantas rite cognitas

Between 1700 and 1900, Mauritius was a key island involved in spreading hibiscus around the world. Many ships called in the port on their way to and from the ports of India, China, and Europe. Mauritius itself was the natural location of 3 of the 8 cross-compatible species of hibiscus. In addition, an Irish surgeon and naturalist, Charles Telfair, settled on Mauritius with his wife Annabella in 1810 when the British occupied Mauritius. Telfair hybridized hibiscus for the next 20 years and kept a written record of his efforts. We don’t know how many of these early hybrids made their way onto ships and thus around the world, but it is likely that many of them did.

This was first done in Hawaii in the first decade of the new century. Our next installment of this article will take a look at the hybridization that resulted in the gorgeous, modern hibiscus hybrids that are available today.By 1900, first and second generation hybrids of Hibiscus were growing in most tropical and sub-tropical areas of the world. Although many improved on the species plants in one way or another, they had not yet attained the flower size and vast array of colors that were to come from more intense hybridization in the 20th Century.There is no complete or even detailed documentation existing today that allows us to trace the early hybrids of Hibiscus made on Mauritius or any of the other places where the species hibiscus were found. It is likely that Kew Gardens in England and other horticultural centers in Europe also created hybrids using these species hibiscus. What we do know is that by the early 1900’s a number of hibiscus hybrids were being used extensively in landscaping throughout the world. The common red single flowered hibiscus, called Brilliant in the USA, is probably the best-known hibiscus in the world. Nobody knows where it came from or when it was hybridized. It seems likely that the single red species on Mauritius, known as Hibiscus fragilis, was either a parent or an ancestor of Brilliant. Also well known by the 1900’s was the pink single known as Pink Versicolor, with similarities to the species H. liliiflorus. An example of a hybrid that came from early European hybridizing is Cooperii, with its unusual variegated leaves.

What Type Of Hibiscus Are There?

Hibiscus are a confusing group of plants!

We get a lot of emails all the time to ask questions about the different types of hibiscus, and unfortunately for all of us, there aren’t really uniform, standardized names for any of the different kinds of hibiscus. Each new type has unofficial names that have cropped up among growers and aficionados, and different groups of people use different names for the same plant or the same name for different plants. Does this all sound confusing? Well, it should! It confuses everyone in the hibiscus world! We hope this article will help sort out some of the terminology and types of hibiscus that we find in gardens around the world.

Tropical Hibiscus v. Hardy or Perennial Hibiscus

The two main groups of hibiscus that we most commonly grow in our gardens are tropical hibiscus and hardywinter-hardy or perennial hibiscus. Tropical hibiscus, as the name describes, originated in tropical climates, stay green year-round, and do not tolerate freezing temperatures. These hibiscuses are all descendants of the tropical species Hibiscus Rosa-Sinensis mixed with seven other species of tropical hibiscus. Tropical hibiscus can only live outside year-round in warm climates where it seldom freezes, and when it does freeze, the cold spell is mild and very short. These are the hibiscus that we associate with Hawaii – the kind that is strung into Hawaiian leis, for example. All our hibiscus at HVH are tropical hibiscus, so northerners have to find ways to winter them in warm places. They have a very long blooming season, from spring through late fall, and into winter in places where it doesn’t freeze. They shed a few leaves at a time all year round, so although they do shed all their leaves each year, it’s not noticeable, because they are covered with green leaves all the time.

Hardy hibiscus, also called “winter-hardy” or “perennial” hibiscus, are most often descended from the species Hibiscus moscheutos or “Rose Mallow”, and sometimes from the species Hibiscus mutabilis or Hibiscus coccineus. Some of the ancestors of this hibiscus were native to the Americas, and all were native to colder parts of the world. Hardy hibiscus dies back all the way to the ground each winter and shoots up new growth each spring. These hibiscuses grow well in cold climates, but don’t grow as well in warmer climates, especially hot, dry climates. Hardy hibiscus blooms in late summer or early fall and have a shorter blooming season than tropical hibiscus.

Hybrid Hibiscus v. Species Hibiscus

The name hybrid can be applied to almost all modern hibiscus. When we use the term at HVH, we are applying it to our tropical hibiscus. But growers of hardy hibiscus use the term hybrid too, as do all growers of all types of hybridized flowers – which means most of the flowers growing in our gardens in modern times. Hybridizing is simply crossing different species or different varieties to produce new varieties. Most types of flowers can be hybridized, and almost all the hibiscus we grow today are hybrids.

The only hibiscus that isn’t hybrids is the original wild species hibiscus that originally grew in the tropics of Asia and islands off of Africa. Species plants, by definition, can self-pollinate and make seeds that will reproduce the same exact plant and flower. If a hybrid hibiscus produces seeds, each seed will produce a completely different hibiscus with an unknown flower, so hybrid hibiscus varieties can’t be reproduced from seed. Only species hibiscus can.

Garden Variety Hibiscus v. Exotic Hibiscus

The terms garden variety and exotic hibiscus are relatively new names in the hibiscus world. Garden variety hibiscus are the ones we are all familiar with from our childhood – the simple hibiscus flowers on large bushes that grew as high as our houses. These are the hibiscus that leis are made from in Hawaii, for example. Garden variety hibiscus are all hybrids, like almost all the hibiscus we are familiar with. But garden variety hybrids are simpler, older hybrids. They usually come in only a single solid color, or possibly a mix of two colors. The flowers are small – mostly the size we now call “mini.”

The new, large, wildly colored, crazily different hibiscus that we grow at Modern Botanicals are what we call exotic hibiscus. In some areas, they are also called fancy hibiscus. Their bushes usually don’t grow as big or as vigorously as garden variety hibiscus, but the flowers are much more spectacular. Exotic hibiscus is all tropical hybrids that must be protected from freezes in the winter. Producing such large multi-colored flowers requires good nutrition and some tender loving care, but there is nothing more rewarding than the beautiful blooms this exotic hibiscus produce.

Grafted v. Grown on their Own Roots

In the early days of hybridizing exotic hibiscus, few cultivars, or varieties, could be grown on their own roots. So almost all exotic hibiscus were grafted onto a tougher garden variety type of rootstock. With the newest modern cultivars, this is changing. Cultivars are being hybridized for their ability to grow their own sturdy root system, so grafting is often not required with today’s exotic hibiscus. At Modern Botanicals, we grow many of our hibiscus on their own roots, but we do also graft some special varieties that can’t be grown any other way. We choose the growing method that creates the strongest, most vigorous plant for each cultivar we grow.

Is Hibiscus Edible?

If your pet or your toddler just munched down part of your hibiscus, don’t panic! Hibiscus are definitely edible by creatures both great and small. Hibiscus flowers are traditionally used for tea in Asia and the Nile Valley area of Africa. Many hibiscus teas are made from a different species of hibiscus, called Hibiscus sabdiriffa, but Hibiscus Rosa-Sinensis, the ancestor of the modern, exotic hibiscus, is also frequently used for tea. Tea makers report that all parts of the hibiscus plant can be used, but that the flowers make a sweeter tea, and the leaves make a more astringent tea.

Hibiscus tea was traditionally used to soothe or help a variety of ailments, from coughs and skin diseases to high blood pressure, gallbladder attacks, heart disease, and even some cancers. Whether these claims have any basis in science or fact, we have no idea. It is known that hibiscus leaves and flowers do contain certain antioxidants, such as flavonoids, and proanthocyanidins, and have a kind of diuretic effect on at least some animals. There have even been a few recent medical studies with animals on the effects of using Hibiscus Rosa-Sinensis flowers as a treatment for certain medical conditions because of these antioxidants, some with successful results. One of the most interesting areas science is currently researching is the use of Hibiscus Rosa-Sinensis to lower blood sugar, and to aid in weight loss! Don’t get too excited and start eating hibiscus flowers by the handful though – this is a brand new area of study with very preliminary results on animals only. No one knows what the effect on humans may be or even what dosage humans would need. Plus, hibiscus is known to have interactions with certain other medications – aspirin among them. Still, it’s an interesting idea that our beautiful hibiscus blossoms may be more than just “another pretty face.”

Hibiscus Rosa-Sinensis is used as a food and food flavoring too. The young, tender leaves of the plant are cooked and eaten in China like spinach. In other places, the most tender leaves are put raw into salads. In various places around the world, the flowers are eaten cooked, raw, pickled, as a spice, or even as a food dye. The flowers are the most used part of the hibiscus plant in cooking. In China, flower petals are baked in cakes, and in India, they are boiled with sugar into a sweet, iced drink. The petals have a mild, tart, citrus taste and can apparently be used for anything that a tart citrus flavor could go with, like rum drinks, fruity or spicy cakes, or even meat dressings. Hibiscus stalks are sometimes added to soups in Central America to give them this same flavor. Some say even the root is edible, although it is supposed to be very tough and mostly tasteless. The plants are safe for animals, but pesticide residue can be harmful.

Even more promising, a 2008 study from the US Department of Agriculture and the American Heart Association found that hibiscus tea lowers blood pressure in adults with mildly high blood pressure! In the study, 3 cups per day of tea made from Hibiscus sabdariffa flowers over a period of 6 weeks lowered systolic blood pressure an average of 7-13 points, and diastolic blood pressure 6.4 points. The higher the participant’s blood pressure was, the bigger the drop tended to be. So people who only needed to lower their blood pressure a little bit did not have the problem of the hibiscus lowering it too much. This is only preliminary data, of course, and further studies are needed to say for sure that hibiscus tea is an effective tool against high blood pressure, but these results look promising. At the very least, it’s nice to know that our favorite plant is not only safe but healthy for any of our loved ones who may happen to munch on it.