One of our top priorities when building our new garden was to install drip irrigation for all the raised garden beds. When it comes to keeping plants healthy and happy, providing deep, even, regular water is just as important as high-quality soil, compost, and sunshine! Yet good irrigation practices often go overlooked. Hand-watering is time consuming, and it’s difficult to be consistent. Plus, setting up automated drip irrigation systems can often feel intimidating… until now!
Follow along and learn how to set up drip irrigation for multiple raised garden beds. Our new raised bed drip irrigation system utilizes drip tape, but the skills you’ll learn today can easily be applied to other types of drip emitters too. This article and accompanying video will walk you through everything you need to know – from supplies to the step-by-step process – to feel confident to set up a similar drip system of your own.
In this article you will find:
- A brief introduction to drip tape irrigation, including frequently asked questions and best practices about spacing, timing, pressure, and winterizing.
- A list of supplies needed to set up drip irrigation to raised garden beds. Nearly everything on this list was purchased through Drip Depot. We’ve been long-time Drip Depot customers, and I recently signed up as an affiliate with them as well. So, we’ll receive a small commission if you shop through our links – which is greatly appreciated and supports our work!
- A YouTube video. I will walk you through the supplies and process of installing drip irrigation for raised garden beds using drip tape. I also show a quick demo of how to glue PVC pipe, and a few other styles of raised bed drip irrigation systems too. If irrigation feels intimidating or confusing to you, it may be best to start by watching the video and then come back to digest everything else!
- A written summary of the steps shown in the video, with plenty of photos of our drip system install.
- Notes for alternative options for installing drip irrigation to raised garden beds (such as using standard ½” irrigation tubing and emitters rather than drip tape).
Drip Irrigation Saves!
Did you know that automatic drip irrigation systems not only save you time and energy, but also save water? Studies show that drip irrigation can save up to 70% more water than overhead sprinkler systems. Rather than spraying everything down willy-nilly, drip irrigation delivers targeted water right at the base of plants and soil. This reduces waste, runoff, and evaporation.
Not to mention, drip irrigation is more efficient and effective at watering plants deeply, rather than only wetting the top few inches of the soil. Deep water means deeper roots, and more resilient, drought-tolerant, and robust plants. All in all, drip irrigation is a win-win – for you, your wallet, plants, and the planet.
What is drip tape?
Drip tape is essentially a flattened version of drip tubing. It lays flat on the soil surface but puffs up once it’s pressurized and full of water. Drip tape comes with drip emitters pre-installed at a set spacing, such as every 6, 9, 12, 18, or 24 inches apart. Each individual emitter will emit a set quantity of water – from 0.25 gallons per hour (GPH) up to 1 GPH depending on the type of drip tape you choose. Drip tape operates at a lower water pressure (8-15 psi) than standard drip irrigation (20-40 psi).
It’s important to note that not all drip tape is created equal. In fact, drip tape often gets a bad rap as being short-lived or even “disposable” because of the way it’s commonly used in big ag. Yet the lifespan of drip tape depends on the quality and thickness of the tape used. We chose the thickest commercial-quality drip tape we could find (15 mil), rated to last up to 10 years when taken care of!
Why we chose drip tape
We chose to use drip tape in our raised bed drip irrigation system for a number of reasons:
- I love the convenience of pre-installed emitters, rather than punching holes and adding emitters to solid ½” irrigation tubing as we’ve done in the past.
- I also like the close emitter spacing that drip tape offers. Our drip tape has emitters every 6 inches. There is another style of round drip tubing with pre-installed emitters (like this one). But from what I saw, 9 inches was the closest emitter spacing available in that type. We’ll talk more about spacing below.
- Drip tape has the reputation of being less prone to clogging than other types of emitter tubing. Drip tape is well-designed not to clog, even when buried below soil or mulch! It was highly recommended by a friend of mine who does professional garden installation and maintenance.
Can you cover or bury drip tape irrigation?
Yes! Drip tape can be installed on the soil surface, buried up to a foot below the soil, or covered with mulch without clogging. Even better, covering drip tape (or other drip irrigation components) can offer protection from sun damage and temperature extremes, thereby extending its lifespan.
In order to keep the very top of our soil well-irrigated, we plan to keep our drip tape fairly close to the soil surface but will cover it with a little soil and mulch. No matter how you choose to install your drip tape lines, be sure that the emitters face upwards.
Spacing drip irrigation in raised garden beds
I recommend spacing drip irrigation in raised garden beds in a way that evenly saturates the whole bed, with the rows no wider than 12” apart. After all, one of the many benefits of growing in raised beds is that you don’t have to follow rigid row planting, unlike traditional field row crops. Plus, the more damp soil there is around, the more the worms, nematodes, and beneficial microbes will thrive! Last but not least, watering in a wide swath around plants (as opposed to directly at their base only) encourages roots to explore, growing larger and wider. That leads to bigger, healthier plants!
In our 4×8’ raised garden beds, we installed the drip lines about 9 inches apart evenly across the bed – or four lines total per bed. Each row of drip tape has .25 gph emitters every 6 inches. This spacing will provide a nice even distribution of water across the entire bed, allowing us to plant along the drip lines or in between. It will be especially great for closely-spaced plantings like root veggies.
It’s best to position the header in one short end of your raised garden bed. Then attach the drip tape (or other drip tubing and emitters) from the header down the length of the garden bed.
How long should I run drip irrigation in raised garden beds?
It depends! Every garden will have different water demands based on the unique climate, season, temperatures and rainfall patterns. It also depends on your mulching practices, and how thirsty your plants are. Larger, mature plants generally “drink” more water than smaller ones. Soil protected with a nice 2 to 4″ layer of mulch will stay damp much longer than bare soil, greatly reducing water needs.
In general, it best to provide less frequent, deep, long watering as opposed to short shallow bouts of water every day. This will encourage deep healthy roots and stronger, more resilient plants. Try to water enough to keep the soil evenly moist at all times, but allow it to dry out ever-so-slightly between watering. Of course, you never want the soil to be totally dry! But remember that plants breathe through their roots – so the soil shouldn’t be constantly sopping wet either.
In our climate, we typically run our raised bed drip irrigation system for about an hour twice per week. The time you run your system will also vary depending on the type of emitters used. For instance, if we were using drip tape with .5 gph emitters (instead of .25 gph), we could run the system for half the amount of time.
When direct-sowing seeds, plan to provide additional overhead or hand-watering during the first few weeks. That will help keep the top of the soil nice and damp during germination and early root development.
Winterizing a raised bed drip irrigation system
As with all types of irrigation, it’s best to winterize your raised bed drip irrigation system before freezing conditions arise. At minimum, thoroughly drain the system and protect it with a nice deep layer of mulch. Leaving standing water in pipes or valves can cause them to crack when the water freezes and expands.
Or, to further reduce the risk of damage, folks in extremely cold climates may want to remove the drip irrigation components completely – storing them in a protected location over winter. There is no need to take the whole system apart however! Use a threaded adapter at the point of connection in each raised bed. Then you can simply unscrew it, remove the entire header and attached drip lines together in one piece, and hang it in the garage (or something similar).
Understanding water pressure in drip irrigation systems
Average household water pressure is around 40 to 60 pounds per square inch, also known as PSI. That is an ideal pressure for sinks, showers and outdoor hose bibs. Yet drip irrigation systems cannot handle such high water pressure. Too much pressure can cause “blowouts” or damage. Therefore, you’ll likely need to add a pressure reducer to your raised bed drip irrigation system.
The best operating pressure for standard drip irrigation tubing and emitters is between 20 to 40 psi. Most times, one pressure reducer at the start of the system is adequate (e.g. where it connects to a faucet or control valve). Our main irrigation valves already had 40 psi pressure reducers installed at the head assembly. Note that lengths of over 100 feet of standard ½” irrigation tubing may start to lose pressure at the farthest end.
Yet drip tape needs even lower pressure, from 8 to 15 psi, depending on the thickness and specifications of the chosen drip tape. ***In order to maintain good water pressure throughout our large garden space, we kept our main PVC lines at 40 psi but then added a 15 psi pressure regulator inside each raised bed before connecting drip tape.***
Supplies Needed for a Raised Bed Drip Irrigation System
Below is a list of the supplies needed to create a drip irrigation system for raised garden beds using drip tape. At the end, I also noted a few alternative supplies and adjustments if you prefer to use standard ½” drip tubing instead of drip tape.
- A main water supply. We ran PVC to each raised bed, and then converted to drip tubing within each bed. However, you can easily run the same type of drip tape irrigation system from a regular faucet or hose bib. This article and video will show you how to attach drip to a hose bib with an automated timer.
- Standard ½” irrigation tubing, which you can buy here in 50 to 1,000-foot rolls. This will be used to create the main “header” that the drip tape lines will attach to.
- An adapter to connect the ½” drip tubing to your main water supply. We used this adapter to convert from threaded ¾” PVC pipe to ½” irrigation tubing (which has an option for ½” threaded pipe size under the same link). On the other hand, this 4-in-1 adapter is ideal to attach drip to a regular faucet or hose bib instead. It includes a pressure reducer, backflow device, filter, and drip tubing connector.
- Optional but recommended: a valve to control or turn off each raised bed individually. Our PVC-to-drip adapter (described just above) has a valve already included. However, you can buy these separate valves to install within your ½” tubing too.
- Pressure reducers. Standard drip systems should be reduced between 20 to 40 psi, which can occur at the main connection (such as at a hose bibb or irrigation valve). Our main irrigation valves already had 40 psi pressure reducers installed. Systems using drip tape must be further reduced to 8 to 15 psi (check your drip tape specifications) so we added an additional 15 psi pressure regulator at each bed. Note that our regulator is made to connect to ¾” pipe thread, but other sizes are available.
- Elbows and/or tee connectors to create the header. We prefer these Perma-loc connectors that screw on over the tubing. They can easily be disconnected as needed for repairs or changes. Rather, these common compression-style connectors are more permanent; things need to be cut apart to make changes.
- Drip tape of choice. We used this heavy-duty 15 mil drip tape with 0.25 gph emitters every 6 inches. The 0.5 gph would be ideal for raised beds too! Drip tape comes in rolls of 100, 500, 1000 feet or more. Run some quick math to determine how much you need. For example, we installed (4) 8-foot rows per 4×8’ bed. So that’s 32 feet per bed X 16 beds (plus a few smaller beds) = about 600 feet. See above for more info on spacing.
- Barbed adapters. We used these 3.6 mm barb adapters to connect the ⅝” drip tape to the ½” header tubing.
- End caps or clamps. We use figure 8 clamps to end the ½” irrigation tubing header. These closure clips are what we used to end each line of drip tape.
- A punch tool. Used to add holes to the ½” irrigation tubing and then connect various adapters or drip emitters to. Here is a simple hand punch, or this option is similar to what we use.
- Stakes, pins or galvanized landscape staples to hold everything in place.
- If you’re working with PVC, you’ll need PVC primer, glue, and a good set of ratchet-style pipe cutters.
- Optional: a timer or controller to automate the system. Our orchard, existing garden, and new raised bed drip irrigation systems are connected to a solar-powered Hunter 6-station controller. The other drip systems we run from hose bibs have this simple faucet timer.
- A backflow preventer and filter. It’s best practice to have a backflow prevention device to stop soil or other contaminants from getting back into your household water supply. Similarly, a filter will prevent debris from entering and clogging your drip irrigation system. There are a few backflow preventer options, depending on your main water supply connection. Hard-piped systems like ours usually have a filter and backflow preventer within the mainline head assembly. Or if you are connecting to a hose bib, use a 4-in-1 faucet adapter – which has a backflow device, filter, pressure reducer and drip connection. You can add a timer too! See photos of both below.
Alternate drip supplies:
If you’d rather use ½” irrigation tubing to create rows instead of drip tape, there are a few adjustments you’ll need to make. One, you can create the main header (just like ours) but use 3/4” poly tubing instead of half-inch tubing for the header. Then, use these barbed adapters to connect ½” tubing to it. Keep in mind you’ll need to purchase 3/4” connectors, elbows, and other adapters for your header assembly in this case.
Another option is to still use ½” tubing in your header, but cut it and install tees every 8-12 inches to attach the lateral lines to. From there, you can connect either pre-perforated ½” drip tubing like this, or regular solid ½” tubing with your own emitters added, such as 1 GPH or 2 GPH drip emitters, or connect micro-sprinklers or bubblers with ¼” micro-tubing. Or, you could even connect 1/4″ drip tubing to a 1/2″ header, shown below.
Installing Drip Irrigation In Raised Garden Beds (video)
Now, please enjoy this video demonstration that will walk you through the installation process. Then, keep scrolling for a written summary and additional photos of our system. Before getting started creating your own raised bed drip irrigation system, draw it all out! That will help you visualize the system as well as develop a list of the parts you need.
Steps to Set Up Drip Irrigation in Raised Garden Beds (written summary)
1) Run water supply lines to each raised garden bed
The main water supply lines may be PVC, other hard piping, or ½” black drip tubing itself. One option is to add water lines and risers concealed under/inside every raised bed, either before the garden beds are installed or trenched under existing beds after-the-fact. Or, simply run the water lines up the outside of the bed wall.
After construction or modifications, flush the main water lines to remove any debris before connecting drip irrigation components or valves. Simply turn them on and let the water run for a few minutes. Keep the lines elevated or otherwise protected from anything getting back in during the process.
Notes on our water line installation:
You’ll see in the photos that we installed our PVC lines on top landscape fabric, under several inches of gravel. However, please keep in mind we live in a mild climate that doesn’t freeze over winter. It also doesn’t get all that hot in summer! Otherwise, it’s best practice in most places to trench and bury pipes at least 6 inches minimum (usually 12″ to 18”) to protect them from freezing or temperature extremes. Therefore, please look into the best practices for irrigation water line installation in your climate.
To offset how shallowly we installed the supply lines, we used schedule 80 PVC (grey) rather than schedule 40 (white). Schedule 80 is thicker, more resilient to temperature swings, and UV-resistant. Unlike white PVC, it won’t get brittle and crack from sun damage. Therefore, schedule 80 is recommended for above-ground installations (or in situations similar to ours). It is more expensive than schedule 40, so only use it if you have to.
2) Convert from the main water supply lines to drip
Next, use an appropriate adapter for your system to connect the main water supply lines to ½” drip irrigation tubing. (That is, unless you’re already using 1/2″ irrigation tubing for your supply lines). The right adapter will depend on your particular supply lines (various sizes of PVC, other hard-piping, a hose bib, etc) as discussed above and in the video. To use the same adapter we used, you’ll want your PVC point-of-connection to have a threaded female fitting. The adapter is available for either 1/2″ or 3/4″ threaded PVC connections, but be sure to choose the 1/2″ Perma-loc size!
3) Assemble the header and drip tape lines
If you’re installing drip irrigation in multiple raised garden beds of the same size, I recommend making one header in/near the garden bed to be sure everything fits and is spaced the way you like it. Then, use that header as your guide or prototype and assemble the remaining headers in a clean work space. (Such as a concrete patio. We even put some together on our dining table.) That way, there is less risk of getting soil inside the parts as you work – which can clog your emitters!
- Measure and cut the solid 1/2″ poly tubing to fit inside one short end of your raised bed. If you’re using figure 8 end clamps like us, leave a couple inches extra to fold over.
- Measure and cut the smaller/side section of the header that will connect to the main water supply/adapter.
- Connect the pieces of header tubing with elbow connectors.
- Measure and mark where you want each row of drip tape to attach, spaced evenly in the bed (between 6 to 12 inches apart).
- Use a punch tool to create holes in the main header tubing. Be sure the holes are oriented in a way that will have the drip tape laying flat on the soil surface.
- Insert barbed adapters into the holes.
- Attach drip tape. Completely loosen the perma-loc nut (exposing as much of the barb as possible), slip the drip tubing over the barb, then hold it in place while you tighten the nut down over it. Remember, keep the emitters facing UP!
- Add end caps/clips to both the main header line and drip tape lines.
4) Install the drip system – and enjoy!
Finally, install your new drip irrigation in the raised garden beds. Pin everything in place with landscape staples. Connect your header to the main water supply, and turn on the system to test it. Tighten or adjust any leaky connections as needed. Cover the drip components with a little soil or mulch if desired to protect it from sun. Now you can sit back, relax, and enjoy your brand new easy, efficient, time-saving raised bed drip irrigation system!
And that concludes this lesson on how to set up drip irrigation in raised beds!
Well folks, I realize I just shared quite a bit of information to digest. Who knew irrigation could be so dry? 😂 But now your garden beds should be the opposite of dry! I hope this article took some of the mystery out irrigation for you. I also hope you now feel prepared and comfortable to install drip irrigation in raised garden beds of your own! Please feel free to ask any questions in the comments below. If you found this information to be valuable, please spread the love by pinning or sharing this post. Thank you so much for tuning in, and happy watering!
You may like these related articles:
- How to Install Drip Irrigation to a Hose Bib or Faucet (video included)
- How to Build a Raised Garden Bed (video included)
- Rainwater Harvesting 101: How to Set up a Rainwater Collection System
- How to Remove or Kill Grass (and Grow Food, Not Lawns!)