Drip Irrigation for Lawns?
Sprinkler heads are becoming more efficient and water smart. Products like Hunter'sMP Rotator heads and K-Rain’s Rotary Nozzles save a lot of water when compared to the old style spray heads. Studies have shown that when watering lawns, the efficiency of the MP Rotators are on a par with drip irrigation. There has been a lot of effort put into developing drip irrigation systems for lawns, i.e. sub-surface irrigation; however, the best solution at this time for lawns is to use a watersense sprinkler head coupled with a smart controller to achieve an advantage over drip irrigation when watering grass.
Where Drip Irrigation Excels
All the other areas in a landscape (like flower beds) that are watered with pop-up sprinklers are much better serviced with drip irrigation. When watering flower beds with sprinklers, a lot of water is wasted in evaporation and on areas that have no plants because the water is indiscriminately distributed overhead. The result is wasting water and watering areas with no plants which encourages weed growth.
Drip Irrigation on the other hand delivers water right to the roots of the plant thereby eliminating water waste, and stifling weed growth as there is no excess water on the soil for weeds to utilize.
How to Convert a Sprinkler Head
It is actually very easy to convert a sprinkler head to drip irrigation. Why? The hard work has already been done. All of the trenching, piping, valve and controller installation has been done. What you have at each sprinkler head is a water source and you just need a few parts to convert that water source into drip irrigation.
We do want to note that you will want to make sure that the sprinkler heads you wish to convert are on a separate zone/valve from your sprinkler heads that will be watering grass. Proper zoning in any irrigation system is important. In this situation, where you have sprinkler heads and drip irrigation, the two are not compatible to run on the same zone. Drip irrigation emits water slowly (think a dripping faucet), which will require a longer water run time in order for plants to get enough water. In the heat of the summer, you may want to run your drip system 30-40 min a day, whereas, sprinkler heads water fast by spraying lots of water. You can imagine that if the two were operating in the same zone, there is no way to find a happy medium for both. If you water for 30-40 minutes every day, your lawn will get an excess of water. Vice versa, if you run it for 15 minutes every two days, your drip irrigation plants will not get enough water. If your lawn and other parts of your landscape are already zoned differently, then converting to drip irrigation is easy.
Step 1 - Remove the Sprinkler Head
The first task will be to determine the sprinkler head to convert and then you will need to remove it. In most cases, you will need to dig down to the connection point of the sprinkler head in order to unscrew the head. The exception would be if the sprinkler head or flood bubbler was installed on a riser. If that is the case, you can just unscrew it from the riser if you're happy with the height of the riser.
If not on a riser and/or you are not happy with the height, you will need to install a new riser at the required height. In most cases, the risers are ½” male pipe threads. This is important to note as you will need to match this in order to convert or extend. Once you get your riser to the needed height, we offer many different options of conversion which are discussed below.
Step 2 - Determine Water Requirements
Before you can install any drip irrigation products, you first have to know how many plants you wish to water and how far away they are from your sprinkler head.
Let’s look at the number of plants to water. There are a number of sprinkler conversion products, some are designed to water single plants and others are for multiple plants. For single plants, there are drip emitters which come on a threaded adapter that allows for direct attachment with a sprinkler riser. These make one plant conversion very easy.
If you wish to water more than one plant, then you will need a multiple outlet manifold. These can also screw directly onto a sprinkler riser. We have models that range from 4 - 9 outlet points. Some models have caps to block unused outlets which is great if you think you may want to expand in the future. You can simply use what you need now, cap the other and have room to expand when the time comes.
An important note to keep in mind when using the drip manifolds is that they are designed to use ¼” tubing which is not an issue unless you wish to water plants that are located more than 30 feet from the drip manifold. ¼” tubing has a maximum run length of 30 feet. After 30 feet, ¼” tubing starts to lose pressure which often results in less water being delivered to your plants. If you need to water plants that are located at a distance of over 30 feet, then we recommend connecting ½” tubing (more on how in the next section).
Step 3 - Installing
Most of the conversion products need to be installed above ground. This means if you dug down to remove the sprinkler head, a riser will be needed in order to get back to ground level. The length of the riser depends on how high you want the conversion item to be off the ground. Screw in your threaded riser to your PVC pipe and then fill in the hole to support the riser.
Now that you are back at ground level, it is time to install the right drip irrigation conversion product for your needs. Below you will find a video showing how to install for single, multiple, and plants that are located greater than 30 feet from your converted sprinkler head.
This one is easy if you use a drip emitter that can adapt right to a sprinkler riser. Some of the products that we have that can do this are:
You will need to use a drip manifold that matches the number of plants you need to water. Again, consider whether you might like to expand your system in the future. If so, then you should get a manifold that can have the unused outlets capped until they are ready for use. We have multiple outlet drip manifolds that come are designed with the following number of outlets: 4, 6, 8 & 9.
Plants More than 30 feet Away:
This installation is a bit more involved than the other scenarios. Here the sprinkler riser needs to be adapted to accept ½” tubing and the water pressure must be reduced. Sprinkler systems operate at a much higher water pressure than drip irrigation; most sprinkler systems are above 35 PSI, whereas most drip systems operate at 25 PSI or less.
You may be wondering whether pressure makes that much of a difference. The answer is yes. If you run high pressures through a drip irrigation system, it may cause fittings to blow off (resulting in leaks) and/or drippers to shoot streams of water instead of drip.
What this means in that scenario is that you will need to start with a FPT x MHT Elbow Adapter. This will allow you to attach a standard drip irrigation head assembly. A head assembly consists of backflow preventer, filter, pressure regulator and tubing adapter. Once these are attached, ½” or greater tubing can be attached and run throughout your landscape. Below is a short video that walks you through this setup.
If you don’t like having this system protruding in your landscape, this could all be assembled below ground and enclosed in a valve box.
Once you have your drip irrigation conversion parts in place, the rest of the setup is just like installing a conventional drip irrigation system. If you need any help or want to learn more about drip irrigation, check out our other resources on drip irrigation installation or contact us at firstname.lastname@example.org.