To grow great hibiscus with lots of colorful blooms, they must be well watered. Watering well is simple, but can be something of a challenge until you determine the best strategies for your microclimate and situation. On this article, we will look at some of the best strategies for watering hibiscus, ones that have proven over time to bring about the best results.
Hibiscus are water-loving plants. They have lots of large leaves, and the blooms are big and full of moisture themselves. In the tropical areas where hibiscus originated, mostly islands or coastal areas, the air is humid and rainfall is plentiful. Most of us are not growing our hibiscus in the tropics, so we need to simulate as much as possible the natural conditions where hibiscus originally developed. That means plenty of water during the warm times of the year. Hibiscus are not built for cold temperatures and don’t know what to do with too much water when it is cold. During cold weather, we continue to water, but we water quite a bit less.
There are two basic aspects to watering well. The first is how often water is applied and the second is how much water is applied. Hibiscus need to be watered often when the weather is warm, and even more when it is hot. In most locations, that means daily watering, unless sufficient rain makes watering unnecessary on a particular day. How much water to apply is determined by how much is required to thoroughly wet the soil around the roots of the plant. In a pot that is easy to determine, but for plants in the ground it is harder. If the hibiscus is growing well, with lots of green foliage, you can assume it is getting sufficient water.
The quality of tap water is an issue in some areas. The pH (acidity) and the amount and kind of minerals in the water can affect plant growth. Hibiscus are fairly tolerant of variations in both these measures of water quality. They grow best in areas where the water is slightly acid (pH 5.5 to 6.5) and were dissolved minerals are low but will grow OK within a range of pH from 5.0 to 7.0 and with moderately hard water. If you know your water is outside these ranges, either very high or low in pH, or very hard with lots of minerals, consult your local County Dept of Agriculture for advice on how best to deal with local water conditions. A Master Gardeners group in the area is also a good source for advice about water quality.
How Often Should I Water?
Water Before Stress Shuts Down Growth and Blooming: However you water – whether by a hose, watering can, sprinkler or drip system – the water must be applied to the soil or potting mix around the roots dries out too much. When the plant cannot get enough water from the media it is growing in, many growths and blooming processes begin to shut down. At first, this shut down is not visible, but it is still happening and will affect the plant’s growth and blooming. If allowed to continue, the hibiscus will visibly wilt. Once water is applied, the wilt will disappear and the leaves will once again appear green and crisp. When this happens, don’t be fooled. Yes, the hibiscus has recovered from the near-death experience, but its future growth and blooming will be affected.
Water more in hot weather to keep hibiscus
like this ‘Cindy’s Heart’ blooming prolifically
Watering well means not allowing wilt to happen, not even the “invisible” pre-wilt shutting down of growth and blooming processes. The biggest cause of a slowdown or stopping of blooms in summer is a lack of sufficient water when the temperatures soar. This is very typical for gardens that are watered the same in spring as in summer. What was sufficient water in spring becomes insufficient water when temperatures rise. Hibiscus can become stressed by late afternoon on hot days, even when watered in the morning. Potted hibiscus, in particular, can use up most of their water by the end of the day, bringing about a stressed condition to the hibiscus that results in a decrease, or even cessation, of blooms. The way to counter this tendency is to water twice a day or to transplant the hibiscus to larger pots that hold more water. For plants in the ground, watering more deeply can provide the extra water that the plants need to deal with the high temperatures of summer.
Water According to the Weather: Water often, but adjust how often according to current conditions. Hotter, drier, sunnier, and windier conditions dry out pots and soil more quickly. Cloudy, rainy, cooler conditions make the water last longer. Be flexible about watering. If drying conditions are present, water more often. When wetter conditions prevail, cut back on watering. We have watered as often as three times per day when conditions called for it and cut back to once a week during rainy, cool times. Winter does not mean not watering at all. Hibiscus survive cold temperatures best if they are well watered before the cold hits. Dried out hibiscus are vulnerable to both cold and insect attack. So don’t let them become too dry! One of the better ways to help hibiscus deal with a frosty night is to sprinkle them with tap water that is well above the cold temperatures of the air.
As a general rule, water hibiscus once per day when summer temperatures are in the 70’s and low 80’s, and twice per day when they reach the upper 80’s and 90’s. If you cannot water them twice per day, then grow them under shade cloth or in larger pots that hold more water. Placing saucers underneath the pots and filling them with water will also help during the hottest times of the year. Self-watering pots are also available that contain a reservoir that sends water to the potting mix as it dries out. Drip systems run by timers are the very best way to control how often hibiscus are watered. Drips systems are not as hard to build as you may think.
How Much Should I Water?
Remember, when watering it is necessary to apply sufficient water to saturate the growing medium around the roots. When watering with a hose or watering can, be patient and water each plant thoroughly. Spend enough time watering each plant so that the water soaks all the way through the root zone and does not run off the top or out the bottom holes before soaking the root zone. An excellent way to make sure you apply enough water is to water each plant twice. The first application will soak partly through the root ball and make it easier to wet the entire root zone with the second application made shortly after the first. Flooding a pot quickly does not give the best results. Some of the water may flow from the top and the rest of it is likely to take the path of least resistance through channels the water creates in the potting mix over time and then out through the holes in the bottom. Much of the potting mix is left dry and untouched if you just flood a pot quickly once with water.
For potted plants, you can check your results by tipping a few plants out of their pots after watering. If not enough water was absorbed by the rootball, you will see a definite line where the water penetrated to and stopped. The soil will be darker above the line where it is wet and lighter below the line where it is dry. When potted plants are watered correctly the entire root ball will appear dark and wet, with no visible line between wet and dry areas. Expect a surprise when you first do this check! What seems like enough water is usually not enough to soak the entire root ball. Try it yourself until you are sure that the amount of water you are applying is sufficient to wet the entire root zone.
For plants in the ground, digging a shallow well around the base of the plant is the safest way to make sure water seeps down through the whole rootball. The well should be wider than the root ball of the plant all the way around. When you fill the well with water, the water will fall straight down through the soil, and water only what is directly under it. So it’s important for the well to cover the whole rootball and extend past it above the ground where your hibiscus will grow new roots. If you fill each well once, let it soak in, then fill it a second time, you should get the entire root zone well saturated with water.
A drip system works best to water many hibiscus plants.
These ‘High Voltage’ hibiscus in pots are on a drip system.
By far the best way to apply the right amount of water to either pots or hibiscus planted in the ground is to set up a drip watering system that drips water into the pot or ground slowly enough that the root zone becomes wet through and through.
Fertigation – the Best Watering Technique for Healthy, Blooming Hibiscus
Fertigation means combining the tasks of watering and fertilizing into one. It can be as simple as mixing fertilizer into a watering can and using this mixture to water your hibiscus. By applying a small amount of fertilizer with every watering, your hibiscus gets a steady diet of the nutrients they need and do not experience famine and feast cycles. Having a steady and regular supply of water and nutrients allows hibiscus to maximize their potential for growth and blooming. If you have more hibiscus than can be watered by a watering can, you can buy a simple hose end attachment, often called a proportioner, that mixes fertilizer and water together as the water passes through the proportioner. All your hibiscus can be watered using the hose proportioner and receive a supply of needed nutrients with every watering. As we have described in the article on drip systems, anyone with a sufficiently large number of hibiscus can be freed from the daily watering task by using a drip system with a fertilizer injector attached to it. Each of these methods of fertigation will help you grow the most attractive, best blooming hibiscus possible.
Water often and water thoroughly for best results with your hibiscus. Combine fertilizer with the water for optimal growth and health of your plants. Adjust water according to weather conditions. If you stick with these guidelines your hibiscus will reward you with great growth and many bright and colorful blooms!
How to Build a Drip Watering System
Some say that leaky faucets led to the discovery of the benefits of drip watering. The story goes that weeds growing huge where the water dripped gave gardeners the first idea that a slow steady drip might be a beneficial way to water. Nowadays we know that leaky faucets are hard on the pocket book (continuing leaks cause a huge loss of water over time) but commercial and home growers have proven time and again that dripping water into the root zone of many plants provides the best plant performance and is the most economical way to water. Many people are tempted to give it a try, but a lack of familiarity with how to do it is what stops most from going ahead. Below we take a practical look at how and why to set up a home drip system.
Why Use a Drip System?
The why is easy. Hibiscus need a plentiful supply of water in the root zone. Plants “drink” their nutrients and minerals dissolved in the water they absorb (including fertilizer) are what plants use to grow and bloom. If Hibiscus do not get enough water during the heat of summer, they will slow down or stop both growing and bloom. They may also drop leaves so that they do not need as much water. In such a case, the plant will look OK, with some green leaves remaining, but it is likely to sit there doing nothing while we wonder what is wrong. We give it fertilizer, but still nothing. So we scratch our heads and perhaps give up. The only problem is likely to be a lack of sufficient water where and when the hibiscus needs it. Once it receives ample water, some time will be needed before growth and flowering resume, but eventually, the hibiscus will come back to life and start making glorious flowers again.
Hibiscus roots are concentrated in the first 2 feet of soil under the ground and directly below the plant canopy. Although some roots will grow further down or out to the side to find water, all you have to do to water hibiscus well is soak it into the first 2 feet of soil below the plant. A very old or large bush may benefit from deeper soaking, but for most hibiscus soaking down 2 feet will be enough. Soil dries from the top down, so by watering hibiscus a little deeper than the roots go, you encourage them to grow downward. Ideally, they will find a water source below the ground, but until this happens they are totally dependent on rain and what you provide. Different types of soils have to water according to their needs. Sandy soil will allow water penetration easily, but will also dry out very quickly. Other soils, such as what we have in our yard, are rocky and resist penetration by water. Heavy clay soils are the hardest to deal with, and usually, require some work before planting. Improving the soil in the garden by adding appropriate organic matter is always a good idea, but that is another topic for another day.
OK, you say, I realize my hibiscus plants need more water. I have a hose and will just soak them more. Actually, that is better in most cases than not watering enough, but it is not ideal. Why? Two main reasons – first it takes a lot of our precious time to soak each plant every day. In the end, it usually turns out not to be every day, and sometimes several days go by without our being able to get to it. Second, in an effort to provide enough water as quickly as possible, most of us will use the full volume of water flow available. In pots this can result in flooding the potting mix, filling air pockets and driving out the vital oxygen that plant roots need. In the ground, this style of watering often results in much of the water flowing off to the side before it has a chance to sink down into the root ball. Uneven watering – either too much or too little – is the normal result when watering with a hose.
Sprinklers are not the answer either, unfortunately. Sprinkler systems are made to water the entire surface area of a yard or garden area, but the water volume is only enough to water the top 2-3 inches of the soil. This is what a lawn needs, so sprinklers work well for lawns, and in fact, lawns are what most sprinkler systems were designed for. But in order to get water down to the bottom of your hibiscus’ root balls, you would have to run your sprinklers for several hours. For most people, before the water ever reaches the necessary soil depth, it will run off the yard onto streets, sidewalks, and driveways, never reaching the bottom roots of your hibiscus plants.
Remember, the goal is to water your hibiscus so that the water penetrates down 2-3 feet and spreads outward 1-2 feet from the main stem of the hibiscus. You can picture a column of water 2-3 feet wide and 2-3 feet deep centered under the hibiscus. A drip system will do this for you naturally. As the water drips from an emitter or similar device, it soaks in and spreads out naturally, without driving the air from the soil or potting mix. Drip systems are normally turned on and off by timers, freeing you to enjoy your garden in other ways than just watering it. Drip watering systems are suitable for potted hibiscus, too. The goal with pots is to soak the entire root ball with about 10 percent of the water draining out of the holes so that salts do not build up inside the pot.
How Much Will a Drip System Cost?
The Basic Layout
1/2″ Black Poly Pipe Laid within 1-6′ of Each Plant
1/4″ Brown Poly Pipe Connects Each emitter to the Black Poly Pipe
Wells around plants hold water from dripper right above roots
The total cost of a complete drip system will be between $50 and $400, depending on how many plants you need to water and how automated you want the system to be. Costs vary according to what the system can or cannot do. The more flexible and convenient the system, the more it is likely to cost. However, a good basic system that can do all that you normally need to do will not cost that much. We were spending an hour a day watering our home garden by hand before installing the system, and consider that our $350 system paid for itself in a week through time saved. Even more important is the improved look and health of our hibiscus once they received enough water from an hour of dripping water each morning. The most expensive part of our system was the emitters. We bought ones that can be adjusted to emit anywhere from 0-10 gallons of water per hour. These cost about $1 each, but non-adjustable ones cost much less. Instead of using adjustable emitters to handle the different water needs of hibiscus that are much different in size, you can also use more than one emitter per plant for the larger plants. For instance, if we had bought 2-gallon-per-hour emitters, we could have used these for all the plants but then added a second emitter for medium-sized plants and a third emitter for our largest hibiscus.
To “do it yourself” you will need some parts, but all of them are available at Home Depot or Lowe’s at a reasonable cost. The main thing to remember is that each company that makes these parts does it a little differently, apparently in an attempt to force you to use their parts exclusively. Unfortunately, their strategy works. When you buy 1/2″ black poly pipe it will vary slightly in diameter according to who makes it. That means you can’t attach one brand to the other, even though both say they are half inch poly pipe. Grrr! Same with the fittings, which are the parts you use to connect extensions or side pipes to each other. My advice is to do all your drip system shopping at either Lowe’s or Home Depot and remember which one you used so you can add to the system in the future without coming up against mismatched sizes.
Of course, you can let your fingers do the walking and call a landscape maintenance company to give you a quote on setting up a system. This is obviously the easiest method and should provide excellent results. But it is much more expensive and perhaps less satisfying than building your own system. If you want to do it yourself, you will save money and really understand your system when it is up and working. It’s not hard to do, even for those with only a small amount of “do it yourself” experience.
Isn’t it Hard to Set up a Drip System? It Must Be Too Hard for Someone Like Me!
That’s the surprising thing about drip systems! They are EASY to set up! Once you decide which hardware store to use, you’ll find all the pieces you need all together in one part of the store so even a beginner can manage to get the right parts. You can stand right there in the store and push the parts together to make sure you got ones that fit each other and come out the way you thought they would. If you’ve tried working on plumbing, can’t even manage to break open a pipe joint with a pipe wrench, and have decided that plumbing just isn’t’ for you, that doesn’t matter with drip systems! The parts just slide together without glue or tools. You don’t have to be strong or smart or know anything about plumbing. If you’re terrible at measuring and planning and drawing little blueprints (as Cindy is!), you can just buy plenty of everything and start laying the 1/2″ poly pipe out on the ground where you think you want it, then just move it around until you find a plan that works. This is the “artistic” approach to building a drip system. It may not be the most efficient way to figure your plan out, but it works just fine. Don’t let your two left thumbs and lack of mechanical, construction, or plumbing ability scare you away from this project. It’s EASY! If Cindy can do this, anyone can!
Here We Go… How to Set up a Basic Drip System for up to 150 Plants
OK, enough of the theory. Let’s get down to the nuts and bolts of how to set up a drip system. Here are the steps to use in building your own drip system:
A Hose Bib (Faucet)
The Easiest Way to Connect Your System
Determine where you can connect to your current water supply: This can be either a hose bib (outside faucet where you connect a hose) or a place where you can cut into an existing water line. If you have no experience working with PVC pipe and water supply lines, you should just use the regular hose bib or faucet connection. You just buy a threaded connector that screws into the faucet, then push the poly pipe onto the connector. No glue or tools are needed! This hose bib connector is the first item on your list of parts.
The Basic Layout
Lay 1/2″ poly pipe between plants.
Run 1/4″ poly pipe to each plant.
Attach drip emitters to 1/4 poly pipe.
Dig small Wells around each plant to hold water.
Use either drip emitters or sprinkler emitters for ground cover plants.
Sketch a plan for the main line of water: Once you know your starting point, draw on paper (or mentally if that works best for you) a plan for laying out the flexible black 1/2″ pipe called “poly pipe” that will be the main water supply for your garden. The pipe should travel from the point of connection at the hose bib around the garden so that the pipe lies within 1 to 6 feet of each hibiscus. The layout can be circular or planned as a grid, with side pipes going off at right angles to the main pipe. The poly pipe is not very flexible but is flexible enough to make a circle over a fairly wide area. If you need it to make a hard turn at some point that is not a problem using a T or L connector which we will discuss later. The idea now is to determine how much poly pipe you will need to buy. It is usually found in 50, 100, and 500-foot lengths and does not cost much so we recommend you get the amount calculated from your drawing and then add a bit extra so you don’t run out and have to make another trip to the store.The layout of the water pipe in the garden can be anything you want. There are parts that slide into the pipe so that the pipe can be connected at various angles, go up steps, curve over arches, turn 90 degrees, and so forth. The most common of such parts are shaped like X, L. T, or Y and are hollow pieces of plastic that are inserted into the 1/2″ pipe. They are made to fit tight enough that water will not leak out, nor will the pipe pull easily from the connector, without glue or any other connection pieces. Our system consists of 250 feet of 1/2″ poly pipe with enough 1/4″ pipe and emitters connected to it to water 150 hibiscus and other plants. The main pipe is laid out in a big circle with a side pipe that extends over a jasmine-covered archway and sidewalk into another flower bed on a different side of the house. Our normal water pressure had been sufficient to water all 150 plants at one time with this system, using settings from 1-8 gallons per hour on the emitters, depending on the size of the plant. So feel free to design the system according to your needs, as almost any setup can be accommodated by this type of system.
A T-Connector at left
An End folded back and held with an End Closer at right
Use either drip emitters or tiny sprinkler emitters for ground cover plants.
We did not discuss visibility of the watering pipes yet. Some people prefer that they are buried as much as possible. This is a lot more work and is not necessary if there is some type of ground cover that will hide them. Others do not mind them and after they are installed never even notice them. If you do decide to bury the 1/2′ pipe, then just dig a shallow trench (4″ deep and 4″ wide is plenty) wherever you want the pipe to be. Do not cover over the pipe until the 1/4 inch pipe is connected and the system has been tested. Covering it makes the addition of new emitters more difficult, but the benefit of not being able to see the pipe is worth it to some.
- Calculate how much 1/2″ poly pipe and how many connectors you need: Roughly measure off your garden and use your sketch to calculate the length of 1/2″ poly pipe you need. Make a list of the various connectors you need to create your planned line: L connectors for corners, T connectors for joining one piece of pipe into the middle of another, end closers for each end you create, stakes to anchor the pipe to the ground. It’s smart to buy more than you think you need! No matter how carefully you calculate, something unforeseen always comes up, or you somehow manage to break a part while you’re working. So calculate what you think you need, and add a bit more of everything to make sure you have what you need.
Roll of Black 1/2″ Poly Pipe (top)
T Connector, Stake to Anchor Pipe to Ground, End Closer (left to right)
Use these parts to lay poly pipe around the garden, between plants.
Count your plants: Each hibiscus (or another plant) is watered by one emitter on a drip system. An emitter is merely a plastic part that allows drips of water to come out when the water pressure is within a certain range. There are many variations on this idea available but what you need to know now is that you need to buy 1 emitter for every plant that is to be watered. Count the plants you intend to water and note the number.
- Decide what type of emitter you want: The end point of the 1/4″ pipe can apply water in many ways. Drippers are one type of emitter. Others are called bubblers when more than a drip of water is allowed to pass through. Some are mini-sprinklers that can spread the water over a larger area, and others are sprayers that spray a small amount of water over a 45, 90. or 180-degree area. You can even attach a small diameter soaker hose to water an area of ground cover. There are many possibilities for using a drip system, but for watering hibiscus, you need to attach as an end point an emitting device that allows 2-8 gallons per hour of water to soak into the ground around the main stem of the hibiscus.
Spiked Dripper for Each Plant (left)
Roll of Brown 1/4″ Poly Pipe (right)
For our drip system, we chose an adjustable 0-10 gallons per hour dripper that come ready-made on a stake, with a built in connector to join it to the 1/4″ poly pipe, and with an included connector to join the 1/4″ pipe to the 1/2″ pipe. It’s called an “Adjustable Dripper on Spike” and it’s made by Dig Manufacturing. (See picture at right) This emitter is easy to use for beginners because you only need one emitter per plant since you can adjust the water flow, and don’t have to buy any extra connectors. They cost $1 each, so they’re more expensive than other emitters, but they work well and they’re easy connected to the system. Plus you save the cost of the 2 connectors.In order to make these emitters gather the water right over the roots of the hibiscus, we dug small wells around the base of each plant. The wells hold the water and allow it to soak down into the roots gradually.
- Calculate how much 1/4″ poly pipe you need: The emitters are connected to the 1/2″ black poly pipe by a smaller flexible pipe that is normally referred to as 1/4″ poly pipe. This is even cheaper than the 1/2″ pipe and available in rolls of 100′. Remember when we planned to place the 1/2″ pipe within 1-6 feet of each plant? That is because we will use the 1/4″ pipe in lengths of 1-6′ to connect each emitter to the 1/2 inch (main) water pipe. So, if you are going to water 50 hibiscus or other plants, and the average distance from the 1/2″ poly pipe is going to be 3 feet, then you will need 50 x 3 or 150 feet of 1/4″ poly pipe. In reality, you allow some slack in this pipe so would purchase 200 feet instead of the 150 feet calculated.
Small Tool to Punch Holes in 1/2″ Pipe
Buy the parts: Now you’re ready to buy the parts. You’ve been making a list as you’ve gone through each step, so you should be ready to go to the store. Make a quick check of your list before you go to make sure it has all these parts:
- connector to join the hose bib (faucet) to the 1/2″ poly pipe
- 1/2″ poly pipe and a rough estimate of how much you need
- T connectors, L connectors, and straight coupler connectors for the 1/2″ poly pipe
- end closers for the 1/2″ poly pipe (they look like a double ring)
- stakes to anchor the 1/2″ poly pipe to the ground
- 1/4″ poly pipe and a rough estimate of how much you need (3′ or so per plant)
- emitters (1-3 per plant, depending on what type you choose)
- connectors that join the 1/4″ pipe to the 1/2″ pipe (if your emitters don’t include them)
- connectors that join the emitters to the 1/4″ pipe (if your emitters don’t include them)
- a tool that punches the correct size hole in the 1/2″ pipe so that the 1/4″ pipe fits without leaking
Ground Stake Pinning 1/2″ Pipe to the Ground (above)
T Connector Joining 2 Pieces of Pipe (below)
The tools you need are:
- sharp pruning shears to cut the 1/2″ and 1/4″ poly pipe.
- hammer to drive small stakes into the ground
Getting all the parts needed is probably the hardest part of building your own watering system. Inevitably more than one trip to the store will be needed. In theory, you will get everything you need the first time, but in reality, it often does not work that well. We know one fellow who prefers to buy more than he needs and then he returns the left over parts for credit. We prefer to keep left over parts for future projects, but anyway you do it the cost is not high.
Assemble Your Drip System
- Put the Main Water Line Together:
- Start by connecting the 1/2″ poly pipe to the hose bib using the connector you bought.
- Then lay out the 1/2″ pipe all around your garden, between your plants, as you planned. Use pruning shears to cut each long piece to the length you want. Lay out all side pieces and extra loops you need to cover all places in your garden. Make sure your 1/2″ pipe runs within 6′ or less of all your plants.
- Join the 1/2″ poly pipe pieces together with plastic connectors – couplers, T’s, L’s, etc. Just push these connectors into the pipe.
- Anchor the 1/2″ pipe to the ground with a few stakes at strategic points, such as at ends, corners, or in the middle of long stretches. Just hammer the stake into the ground and the hook at the top will catch and hold the pipe.
- Flush and Close the System:
End Connector Closing End (double rings below)
Stake Pinning 1/2″ Pipe End to Ground (above)
Once the 1/2″ pipe is in place and connected everywhere, run the water through it to test that all connections hold and to clean any plastic debris or dirt out of the pipes so that this debris does not clog the emitters later on. When it is all flushed out and watertight, close all open ends of the 1/2″ pipe with plastic end closers. An end closer is just a set of two plastic rings. Thread the end of the 1/2″ pipe through one ring, fold the end (it’s the fold that closes the pipe), and thread it back through the second ring to hold the fold in place.
- Attach Emitters: Now you’re ready to attach your emitters. For each plant in your garden:
- Pick a spot on the 1/2″ poly pipe that is closest to the plant, and use the special tool to punch a hole in the 1/2″ pipe.
- Cut a piece of 1/4″ pipe long enough to reach to the plant, allowing a little extra slack.
- Find the connector that came with your emitter (in our case, it was attached to the emitter, and we just had to snap it off), and push it into the hole you just made in the 1/2″ pipe.
- Push the piece of 1/4″ pipe you just cut onto the connector to join it securely to the 1/2″ pipe.
- Attach the emitter to the other end of the 1/4″ pipe. If your emitter does not have a built-in connector, you will need to use a separate connector. Ours had a built-in connector and attached directly to the 1/4″ pipe.
Emitter attaches to 1/4″ pipe (left)
1/4″ pipe attaches to 1/2″ pipe (right)
Emitter spike is pushed into the ground
Stake the emitter to the ground very close to the base of the plant by pushing the spike of the emitter into the ground.
- If your emitter is adjustable, open it a little bit by twisting the top. You can adjust the exact amount later when you get the whole system going.
Move on and repeat this process to attach an emitter for every plant in your garden.
Turn on the water at the faucet, then adjust each emitter to get the water flow you want for each plant. When the flow is perfect for each plant, leave the water on for about an hour to water your garden. Voila! You now have a drip system!
If you have more than 150 plants, build two or three of these drip systems – one for each 50-75 plants, depending on your water pressure. Either connect the systems to separate hose bibs or use a splitter on a single hose bib to connect two systems to one bib. You can build as many drip systems as you need for the size of your yard. Most people’s water pressure can only handle watering one system at a time, so when you water, run each drip system separately.
How to Add a Timer & Fertilizer Injector to your Drip System
Control the Drip
Once you’ve built or planned your drip system, you need to decide how best to use the system. Drip systems can be controlled manually, but that is missing one of the big advantages of having such a system. It is easy to control the watering schedule using a battery powered timer and a special valve called an “electric solenoid valve.” The timer tells the valve when to open, allowing the water to flow into the system, then when to shut, cutting off the water from the system. We set ours to open for one hour in the early morning. By the time we first see the garden in the light of dawn our hibiscus are already fully watered for the day. Before this, we had to find at least an hour every day to walk around with a hose, watering each of the over 100 plants one at a time. Some days we just could not get to it, other times we felt rushed and would give each plant only the minimum amount to keep it alive. Forget to go away for a vacation! Now, with the timer activating the drip system automatically each day, we are free to enjoy the garden whenever we want without being tied to the job of watering it every day in summer.
Fertilize With the Drip System
Fertilizer Applicator/Filter (DIG Brand)
We all know about best intentions. Fertilizing our hibiscus is one of those jobs we all intend to do but… Fortunately, once a drip system is set up, the job of fertilizing our plants can become much easier and faster. The DIG Company offers an inexpensive addition for drip systems (available at Home Depot and elsewhere for under $15) that will handle fertilizing for you. It is not entirely automatic, but all you have to do is twist off the top of the unit and pour the HVH Special Blend fertilizer or Booster into the unit until full. Twist the top back on and you’re done! The next time the drip system is used the fertilizer will dissolve in the water as it passes through the unit, and will be carried by the drip system to all the plants on the system. This Fertilizer Unit is also a filter for the system and filters out small particles that can clog the drippers. Whether used for fertilizing or not, this unit serves an important function all the time by filtering the water that enters the drip system. It can be used with either manually controlled or timer-controlled drip systems and is we recommend it highly!
Types of Timers
Timers come in all flavors, from hugely complicated ones that can control all sorts of devices throughout a large nursery, to simple, inexpensive ones that only do one thing. This latter is what we want for a home garden. Some timers can be hardwired into the home electrical system. A few are even solar powered. But the one we use and recommend for its ease of installation and low cost runs on one 9-volt battery that lasts 1-2 years before needing to be replaced. No wiring is required! This timer activates an electric “solenoid” valve. Although these valves are available separately from timers, it is easiest to buy one that is already attached to a timer and sold as one unit. As mentioned before, these units, along with all other parts of the drip system, can be purchased economically at Home Depot, Lowe’s, or at a specialty irrigation store. Many smaller hardware stores also carry them. We purchased our DIG Model 7001 Battery Operated Irrigation timer /valve unit at our local Home Depot for less than $50.
Irrigation Timer (DIG Brand)
The installation for both the timer and the fertilizer injector/filter is easy and done at the same time. The fertilizer injector/filter comes packaged with several different types of connectors so that it can be installed in most situations without additional parts. The timer is first connected to the water source for the system, and the fertilizer injector/filter is then connected to the timer on the downstream side of the timer. The downstream side of the Injector/Filter is then connected to the drip system pipe.
To better describe the flow of water to your drip system, think of it like this – the water flows from your hose faucet or from the manual valve on a direct PVC system to the timer, then from the timer to the fertilizer injector/filter, and from there into the drip system and out the individual drippers to the plants. Along the way, fertilizer is added if you have filled the fertilizer reservoir, and all small particles are removed by the filter. It is the timer that allows the water to enter the system by opening a valve at the time you select and then closing it at the time you select to stop the flow of water.
If your system is connected to a hose faucet or to a hose, all you have to do is screw the adapters that are included into the timer, and then screw the other end of the adapter onto the faucet or hose. If your drip system is connected directly to PVC pipe, there is also a connector included with the timer that screws directly onto the pipe.
The Fertilizer/Filter unit also has adapters included that allow it to be connected directly to the timer on one end and directly to the poly water pipe on the other end. It may take some fiddling with parts to get everything connected together, but once you figure out which parts connect the system together, it is a fairly easy task to hook them up.
Install the Battery
Fertilizer Injector & Timer Installed
Black Unit at top is Fertilizer Injector
(Unscrew to fill with fertilizer.)
Blue Unit at Bottom is Timer
(Blue cover opens to set the timer.)
The timer uses one 9-volt battery to operate. This battery must be purchased separately but will last for at least a year. The timer part of the timer lifts off of the lower part of the unit which houses the valve. It remains connected by a cord, but removing it allows for you to stand up or sit comfortably nearby while inserting the battery and setting up the timer. The battery compartment door is on the bottom of the timer, the side opposite the settings. After opening the battery door insert the battery into the compartment, attaching negative and positive connections to the appropriate poles. This is marked inside the compartment and described in detail in the directions that come with the timer. Close the battery door and get comfortable so you can set the timer without feeling the strain of squatting in an awkward position.
If you feel thoroughly confused by all this, don’t worry! These timers and fertilizer injectors come with excellent, clear instructions that are easy to follow. In an article like this, it’s impossible to provide instructions for every type of component you might buy. If you understand the basic concept, installing the parts will be easy.
Setting the timer
OK, we’ve now got the entire system in place. The question now is, how do we use it? The timer, consisting of a timer and a valve, is easy to set. The directions included with the timer you buy will walk you through the steps using diagrams and words that are very user-friendly. For instance, it will show you how to set the time of day you want the timer to open the valve and start the water. It then asks you how long you want the water to flow. In our conditions with the plants we have, one hour works great. Then you select the days you want the system to operate. In summer every day is best, although in rainy climates every other day may be better. There is also a button that lets you skip one day any time that button is pushed, so on a rainy day you can push that button and no water will flow thru the system until the next day. There is also a manual on and off switch that you can activate anytime that turns the system “on” for whatever length of time is already set for automatic operation. This is useful for many tasks such as checking the drippers to see if the amount of water dripping out of them is what you want.
Special Tip For Potted Plants
There is no reason not to put potted plants on a drip system. All our greenhouse plants are in pots and they all have drippers in the pot. The main difference compared to in the ground hibiscus is that most pots do not contain sufficient soil to keep them from drying out during hot summer days. Large pots almost always have large plants in them and they will get sucked dry of water just as fast as the smaller pots with smaller plants in them. So what is the solution to keeping potted hibiscus happy, growing, and flowering in midsummer? Set your timer for more than once per day. Instead of the deep soak for an hour that in the ground-plants need, use a shorter time such as 10 minutes for the system to drip water into the pots. BUT, set the timer to do this 2 or even 3 times per day, and watch the difference this will make to your potted hibiscus. University research has proven this to be the best way to water pots in nurseries, and if you try it, your results will almost certainly bear this out.
The Final Results
Plenty of Water Makes Plenty of Hibiscus Flowers!
Once the timer is set, watering becomes automatic. You can change this anytime you want, but until you do, the hibiscus will receive water every day that you set the timer to water them – automatically! This is the very best way to water your garden. Dripping water into the root zone for about an hour a day will make a huge difference in the appearance of your plants. We knew this from watering with a drip system in the greenhouse but were surprised at just how much better our garden plants looked and bloomed with an automatic drip system in the garden. The difference is impressive and well worth the time and cost to install the system.
We often hear people complain about a lack of blooms in midsummer, which is always puzzling because our hibiscus in the greenhouse never stops blooming, despite the extremely high summer temperatures inside. My best guess is that most people do not provide adequate midsummer water to their hibiscus and our experience with our own garden seems to confirm this. Sure you need to keep insects such as thrips from causing bud drop, and you need to keep fertilizer levels up, but by far the most important influence on the hibiscus in summer is deep, regular watering that keeps moisture available in the root zone at all times.
Sometimes people say, “The soil is moist, I can feel it, so why should I add more?” A little-known fact is that hibiscus roots can only obtain enough moisture from soil or potting mix when that soil is 50% or more saturated. When the moisture level drops below 50% saturation, the roots have to compete with the soil for the water and cannot take enough out of the soil to fulfill their needs on a hot day. Only when the level is over 50% saturated can the hibiscus roots easily obtain what they need from the moist soil. Think about a wet dishrag. When it is first wet it is almost totally saturated. If you wring it out, then you get a lot of water easily. But even though it feels moist after wringing when you squeeze it again you get at most just a few drops of water. The soil is a lot like that – there has to be ample water in it for the hibiscus to be able to get it.
Of course, there are more things you can do with your drip system now that you have it. You can add in little soaker hoses for ground cover areas, or bigger emitters for trees, or little sprinklers for grassy or mossy areas. Once you have the basic system in place and know how to add things to it, you’ll find yourself getting very creative with it. There’s nothing like building it yourself to give you the confidence to tailor it to the needs of your own yard! So have fun and good luck with your new watering system! We know you will thoroughly enjoy having a watering system in place and that your hibiscus will flourish like never before!