Setting up an automatic irrigation system for your medium to large garden
Water is perhaps the most critical ingredient for life as we know it, and perhaps no where is that more apparent than in the garden. No matter where you live, there are bound to be times of year when nature doesn’t cooperate and you are forced to supplement the natural precipitation with some form of irrigation. Here in Illinois, we can get buckets of rain in just a few hours but then have it followed with desiccating heat and humidity that bakes the soil to concrete. On average, the natural moisture might be adequate. But life isn’t lived in averages, it’s lived day-by-day, hour-by-hour. During those long, hot, dry stretches your garden isn’t going to care it rained a week ago. It needs a drink today!
Q: Why is your kit more expensive than the one from another retailer?
A: Great question! The old adage “you get what you pay for” is highly applicable here. First off, our kit comes with an automatic timer and all the necessary parts and fittings for a simple install (additional fittings may be required depending on your installation). Second, and most importantly, our growers at Greenhouse Megastore field tested several iterations of this to guarantee that our kit is guaranteed to work for you. Several similar kits from other retailers available at price points less than ours contain parts and fittings that we are confident will not work for you out of the box without additional hassle on your part. Forget all that, and go with a proven solution!
Water is so important to your garden not only because it hydrates the plants. Water hydrates the soil, and the soil is where the real magic of your garden happens. Trillions of microscopic and macroscopic life forms engage in a delicate dance that breaks down organic matter and releases it’s nutrients to the soil where it becomes available for use by the plants you’ve placed there. Water creates the environment that makes life in the soil possible. When proper watering is one of gardening legend Joe Lamp’l’s 5 Steps to Your Best Garden Ever, you know it’s not just important, but absolutely critical.
Step Up from Hand Watering
The most common type of irrigation in the garden is going to be hand watering by garden hose. While this is a fine method if you have a small garden and your water source is close by, or you just need to supplement a little extra water, it fails to scale to a garden that’s any more than a few dozen square feet. It’s just simply too time consuming to stand in the hot sun and adequately water the varied plants in your landscape.
That’s where an irrigation system comes in to play. An irrigation system is a water delivery method that can be turned on to provide water to your garden and landscape without the requirement of your watchful eye. Many times, these systems are linked to controllers of different kinds that can automatically turn the water on and off during the day in such a way to provide the right amount of water for your plants. Some even link to the Internet and can be controlled with a mobile device, and even know when to delay watering when the weather changes.
Drip Irrigation in Your Garden
The irrigation method we’d most highly recommend in your garden is drip irrigation. Drip irrigation has been highly refined in drier parts of the world in order to take the fullest advantage of scarce water resources. Drip irrigation consists of special tubing that drips at a constant rate from special valves spaced along it called emitters. A drip irrigation system can be highly specific and specialized, but in the home garden a standard flow rate of .5 gallons per minute and a run time of about an hour a day will generally supply a garden with the water it needs to thrive (equivalent to about an inch of precipitation per week).
There are other types of irrigation systems available to you, but none of them maximize water usage like a drip system. Misting or spraying, for example, has an extraordinary amount of waste due to evaporation of water droplets exposed to the air and indiscriminate spray patterns. A drip irrigation system, especially one placed in-ground or under mulch, has virtually zero waste and uses very little water over the course of a season. Drip irrigation is both environmentally and economically friendly.
The Market Gardener’s Irrigation System
Our system was custom designed by the grower’s at Greenhouse Megastore using parts by Netafim, a world leader in agricultural drip irrigation. Though a wealth of knowledge exists on the topic of irrigation, we noticed there was a severe lack of pre-designed kits that worked, were easy to put together, and could scale up in the mid-to-large sized garden, truck garden, or market garden. So, we took it upon ourselves to scout the competition, test some configurations, and provide a solution that was economical, simple to install, and easy-to-use. We deployed this solution (in several iterations) in the gardens of some of our beloved gardeners at Greenhouse Megastore, heard their feedback, and feel positively certain our drip irrigation kit will help you take your garden from good to great.
What’s in our Drip Irrigation Kit?
The hose adapter is simply the piece that allows connection of your drip irrigation system to a garden hose or standard outdoor hose bib. That’s it. For some reason, hose threads are unique to hoses and hose bibs, but plumping pipe is made with standard 3/4 in. threads. These are not the same, and if you try to thread one on the other, you’ll end up stripping the threads and you’ll have a poor connection. This adapter screws on to a hose or hose bib and makes a water tight connection.
Our kit is designed for you to run a hose to your garden and attach it to your drip irrigation system directly using the hose adapter. There is some flexibility in how you ultimately choose to do this, one variation of which I will show later with the system I installed.
The filter included in our drip irrigation kit is just a simple, 120 micron mesh filter designed mostly to filter hard and/or well water. If your water isn’t filtered down to this point, particulates in the water can clog the emitters in your dripline, thus rendering your system less efficient or worse, cause it to fail completely.
Without the proper line pressure in the system, the drip emitters won’t function properly. Or (as in my case with an early prototype) the lines might burst because the pressure is too high. Either way, we’ve sized the pressure regulator to perfectly that required of the system so the emitter’s work correctly and the integrity of the drip lines is maintained. The regulator that comes with the system is a 15psi regulator.
Poly Tube Adapter
This adapter simply threads into the pressure regulator and/or the hose adapter with standard 3/4 in. threads. The other side is a barb fitting that accomodates either 16mm or 3/4 in. poly tubing. Our kit comes with 16mm tubing, but you may consider upgrading if you have to run water line for a long distance before feeding drip lines to your garden, or, if you have a large number of drip lines to feed.
The barbed fitting allows you to just press (with not a small amount of force) the plastic tubing over the barb for a secure connection. You may consider some form of hose clamp at this connection to really insure it’s watertight.
The polyethylene tubing in the kit serves as what’s called a “trunk” line. Basically, it’s the feed line to your garden from the hose connection. This can either be a long or short distance depending on your garden setup. Our kit comes with 100 ft. of 16mm tubing so you should be able to supply water to your garden no matter where your outside faucet might be.
Keep in mind that poly tubing can be routed in any number of ways using additional fittings, such as 90deg elbows and T fittings (not all of which are included in the kit). For instance, mine runs from a faucet on the side of my house, underneath some landscaping and into the side of my garage. From there it runs across the rafters and out the opposite side of the garage where I installed the manifold. I even installed a second hose bib so I had a hose connection closer to the garden. I use elbows and Ts at several points, both to make a clean, aesthetically pleasing look, but also to keep the tubing out of the way so it’s not a tripping hazard and so it won’t get kinked. The tubing can even be shallowly buried for a semi-permanent install (but make sure to disconnect and drain all the lines when the freeze sets in for winter).
Drip Tape (Drip Tube, Drip Line)
Drip tape, or drip tubing, is where the magic happens. We’ve specially selected thinwall drip tape with integrated emitters for ease of installation. Simply measure out the length of a run and cut it with a razor or scissors and connect it to the trunk line. Once the system is turned on and pressurized, the emitters in the drip tape will drip at a constant rate of about a half gallon per hour. In most cases, running the system for about an hour per day will be enough to keep your garden well hydrated.
Twist Lock Fittings
Special fittings for the drip tape round out our kit. There are several available for this purpose, but we chose the Twist Lock variety. Even though they are marginally more expensive, they fasten more securely and can be installed quickly with no additional tools and so they are perfect for the garden setting. They work by simply sliding the drip tape onto the appropriate barb end and then screwing the collar down tightly to lock the tube in place and prevent leaks. Make sure these are tight! Else the drip tape might pop off under pressure (trust me, this CAN happen). The above pictured fitting transitions the 16mm poly tubing to the drip tape and includes an integrated shut off valve, handy when you want to shut down one line for maintenance or other reasons.
We also send a few couplers, in case you get a line burst or accidently punch a hole in a drip line.
The Twist Lock couplers awesome little fittings designed so that you don’t have to install a whole new run of drip tape when you inevitably get a failure in one of your lines. You simply cut out the failure point, and install the coupler. For me this had to be done several times when my lines burst due to installing the incorrect pressure regulator, but also because I accidently punctured one of the lines while I was hoeing weeds (keep your hoes sharp, folks). This sort of stuff WILL happen, and is why we ship a few of these couplers with our system.
Lastly, the kit includes Twist Lock drip tape ends. These are just Twist Lock fittings that act as a plug on the end of the drip lines and allow the system to maintain pressure. Without these, water would just flow out the ends of the drip lines, which would be both wasteful and pointless.
At first I tried to just tie a knot in the drip tape, then I tried kinking and duct tape. Suffice it to say, the only way to truly terminate a drip line is with a fitting specifically designed for that purpose. That’s where these ends come in. It’s simply a Twist Lock collar on one side and a plug. These ends are nice because they are designed so that you can place a stake through them and into your garden bed, thereby ensuring your drip line will stay in place through all the activity that goes on in your garden.
Ep. 112 – Efficient Watering in the Garden and Landscape and Why it Matters of the highly recommended podcast The Joe Gardener Show hosted by legendary gardener and TV personality Joe Lamp’l.
Our kit does not come with a controller, but in almost all cases I’d recommend at least this very simple one. There are other, similar, ones that even connect to WiFi and can be controlled from anywhere in the world and are even intelligent and know when to skip a day of watering because it rained.
The pictured controller allows you to set a time interval down to every 6 hours for the controller to be open and the water flowing. You can also specify a run time for the water as well. For instance, if the goal is about an hour of watering per day, then you can set the controller to activate every 6 hours for 15 minutes. That’s 4x per day at 15 minutes and so is an hour of runtime. You can set it for every 12 hours or once per day too, so your options are very flexible.
Once the controller is installed and setup, you literally never have to worry about watering again (other than to make sure your lines aren’t busted and other regular maintenance). That’s the goal that Greenhouse Megastore set out with. To see if we could take the worry out of watering your garden. The best products are always those you never end up thinking about once you have them, and we know you’ll feel that way about this drip irrigation system! Let us know in the comments if you have any tips, tricks, or recommendations, and happy gardening.
Real World Install
Here you can clearly see the hose bib manifold I purchased separate from this kit (so I could have multiple connections at a single faucet). On the left, you can see the hose adapter threaded onto one faucet, with the Poly adapter threaded into it. I used white teflon plumbing tape on the threads and tightened it to ensure no leaks. Then I fitted white poly tubing onto the barbed end of the Poly tube adapter. I used dish soap to lubricate the barb end, and a hair dryer to soften the tubing. Then I pressed the tubing onto the barb end. This can take considerable force, so any method to make it easier is almost required. If you find something easier than what I did, let us know in the comments!
I ran my tubing from my house, through the garage, to the garden on the other side. I used these additional fittings to clean up those connections. This is mostly to avoid kinking the tubing, which will render your system useless and possibly break your tubing.
The poly tubing transitions to another Poly adapter, which threads into a 3/4 in. threaded coupling. This then threads to the mesh filter. Be sure to use white teflon tape on ALL threaded connections. Also make sure to check the directional flow arrow that is marked on the filter. You want the water moving in the direction of the arrow.
After the filter comes the pressure regulator. The one for our system can thread directly onto the filter. Again, use white teflon for the threaded connections and make sure the regulator is installed so that the water is moving in the direction of the flow arrow marked on the regulator body.
In our kit, a Poly adapter will thread directly into the regulator and an additional length of poly tubing will run to your garden. For my install, I chose to put a hose bib on the regulator so that I could install a timer at that location. In this way, I can set the timer and have it operate only for the garden. I still have water at the other faucet locations even if the irrigation system is off. (Note that the bottom of the controller is really just another hose bib connection.)
I also chose to install an additional hose bib on the side of the garage so that I could hand water the garden when necessary (and so my kids could play with the hose without dragging it across the driveway).
For each run of drip tape, you must install a T fitting in the poly tubing with a ~6 in. piece of poly tubing. To this, you must attach a Twist Lok shutoff valve. One end accommodates the poly tubing, and the other the thinwall drip tape. By sliding the drip tape over the barbed fitting and securely tightening the threaded collar, you ensure a tight, durable fit with no additional tools required. If you don’t securely tighten the Twist Lock fittings, the drip tape may “pop” off the fitting when the system is pressurized.
Other than that one “gotcha”, all in all it’s a great and easy system to install and use. Once this kit was installed and running, I immediately saw the plants and the soil respond. Scraping back the mulch revealed moist soil to an adequate depth, and a the deep green flush of healthy growth started in the growth zones of all my plants and moved it’s way inward, as the plants themselves popped new leaves faster than before. Now all I need to do is check the system regularly for proper function, and make sure I (try) to keep up in knocking back the weeds in the beds. So far, I’m thrilled with the results of this simple installation! Let us know what you think, how it went for you, and any improvement ideas you might have in the comments below!