DIY Patio Irrigation System

With summer temperatures in excess of 110 degrees for most of the summer, adequate water is very important to the health and viability of your landscape plants.  Living in a townhouse, I have a small courtyard patio and most of my landscape plants are in containers.  Because of this, ensuring that my plants receive enough water throughout the summer is extremely important.  It seems that every year I lose one or two plants to lack of water because, quite frankly, I forget to water them. Last winter I installed a drip irrigation system so that this summer, my plants will thrive in the desert heat. All supplies were purchased at Home Depot and I spent less than $100 total.

Drip Irrigation Supplies

The above image shows the supplies I purchased at Home Depot. Now let’s get started. The first step is to lay out your 1/2 inch drip tubing along the perimeter of your patio and cut into pieces for each segment. Note that this tubing is designed to be buried but will be okay when left above ground. Using the 90 degree ell compression fittings, you’ll need to insert the end of the tubing into the fitting. Be prepared to use a little elbow grease here, it takes a bit of pressure to properly seat the fitting over the tubing. I’ve found that by grasping the tubing approximately 3-4 inches below one end and working the fitting back and forth (clockwise, counterclockwise, clockwise, etc.) while pressing together, the fitting will seat. You should feel the tubing hit the stopper when it is properly seated.

Tubing with 90 degree ell

Once your 1/2 inch tubing is in place, you can then attach the end caps as needed.  The end caps have a threaded cap that can be unscrewed to flush any dirt or debris that might work its way into the system. This shouldn’t be an issue if the tubing will be left above ground, but if you plan to bury your tubing, be sure to flush the system before installing the 1/4 inch drip tubing. The next step in our project is to install the controller and connect it to our pipe. There are three fittings in addition to the controller that are very important.  The first is the backflow preventer. This keeps the irrigation water from backing up into your potable water supply in your house, should the irrigation line become clogged. The second fitting is the pressure reducer.  The water pressure from your hose bib can be anywhere from 40-75 pounds per square inch (PSI) as it exits the spigot. I chose a 20 psi reducer so that I don’t blow the emitters off of the 1/4 inch drip tubing when the system kicks on.

The controller

The controller connected to the spigot.

The third fitting is the threaded adaptor that allows you to connect the pressure reducer to the 1/2 inch supply tubing. This is illustrated in the photo above. The completed controller setup is shown below. Once it is all connected, unscrew the end caps and flush the system until clear water exits the tubing at all ends.

The completed controller assembly

When the system is flushed, reattach the end caps and position your containers where you’ll want them. Once in position, measure enough 1/4 inch drip tubing to extend from the 1/2 inch supply tubing to the top of the container and cut to length.  I’ve found it’s easier to attach the emitter and barb connector to the drip tubing before inserting the barb connector to the 1/2 inch supply tubing. Using the punch you’ll punch a hole into the 1/2 inch supply tubing as shown below.

Barb connector and punch.

Punching hole for 1/4 inch drip tubing.

Hole punched in 1/2 inch tubing

Once you’ve made the hole in your 1/2 inch supply tubing, insert the barb connector with the 1/4 inch drip tubing attached and secure in the container with a stabilizing stake.  A quick note on emitters: Emitters are available in various forms. There are color coded emitters that are available in 1/2 gallon per hour (GPH), 1 GPH, and 2 GPH.  There are also emitters that allow you to adjust the flow rate by twisting the top of the emitter. I prefer these emitters because I can adjust the amount of water given to each plant based on plant type and container size and provide sufficient water without overfilling the container. Once you’ve installed drip tubing to each of your plants you are ready to program your controller. Be sure to leave your spigot turned on so that when the controller turns on water will flow through the system.  Also, if you can’t dedicate a spigot to your irrigation system exclusively, you can install a “wye” hose connection to the spigot and have one side open and always on for the irrigation system and the other side can be manually turned on and off when needed. For seasonal watering guidelines, here’s a great resource from the Water Use it Wisely website. As always, I hope this guide has been beneficial to you.  Feel free to reach me on Twitter if you have any questions or send me an email (see below for email address).