I’ve been a fan of drip irrigation since we installed it in our polytunnel. But for some reason, it never occurred to me that drip irrigation would work for raised beds, too! Then, my husband asked me why I hadn’t installed drip irrigation for my raised beds near the house. He seemingly read my mind. So – yet another garden project began!
And – we documented every step of the process.
We’ll share it below!
- How to Install Drip Irrigation for Raised Beds In 5 Easy Steps
- How Do You Keep a Raised Bed Wet?
- How Much Water Does a Raised Garden Bed Need?
How to Install Drip Irrigation for Raised Beds In 5 Easy Steps
We’re about to share our easy, 5-step method to install drip irrigation for nearly any raised garden bed setup. But first – let’s quickly distinguish between irrigation soakers and drip irrigation.
The two most popular types of irrigation are soaker hoses and drip irrigation, and we use both types in our vegetable garden and food forest. They both work well in this flat garden area, but which would be the best choice for our raised beds?
Soaker hoses can irrigate raised beds. But, we found drip irrigation was easier to install and set up. Drip irrigation also gave us greater control over how much water each area of the garden received, allowing us to turn off emitters when certain crops finished for the year.
Another benefit of garden drip irrigation is the even distribution of water provided directly to the entire root network.
The best part is that installing drip irrigation for your raised garden is surprisingly easy. Here is our 5-step process for installing drip irrigation for nearly any raised bed garden setup.
Step 1. Planning Your Drip Irrigation Layout
First – plan the raised bed drip irrigation layout. Planning the drip irrigation layout will determine how many connectors, bends, and emitters you need and the total length of irrigation pipe required.
When planning the drip irrigation layout – keep track of how many square feet of raised garden you need to water.
A garden drip irrigation kit should meet your needs for one or two raised beds. We had several different-sized beds to cover, so we went for an extended irrigation system with components sold separately.
Automatic drip irrigation kits are the perfect watering method for growing closely spaced plantings. Keeping the soil covered with plant growth slows water evaporation rates and can reduce overall water usage, even during extreme temperature swings.
Step 2. Establish Your Drip Line Spacing
Use the directions for any drip irrigation system to calculate your drip line spacing. Some emitters reach slightly further than others.
We get good water coverage of the entire garden by spacing drip irrigation tubing 12 inches apart in a grid system. Most of our raised beds are approximately three feet wide, so we have three drip lines in each bed, with the outer row of drip tape lines around six inches from the edge.
Many gardeners mistakenly think that drip irrigation only supplies water directly to the area around the emitters. Yes, you will only see a small space of damp soil directly below each emitter, but dig down a few inches, and you will find that the water has dispersed horizontally and vertically. This horizontal movement is due to capillary action and is more pronounced in clay soil vs. sandy soil.
Step 3. Determining How Many Emitters You Need
Once you plan your drip irrigation layout and spacing, you then figure out how many emitters you need. Placing drip emitters at 10-inch intervals along each section of standard drip irrigation tubing provides good soil moisture levels in our raised beds, as the soil is rich in organic matter and retains moisture well. So, for a 6-foot-long raised bed, you would need five or six drip devices along each length of black drip tubing.
So, now you’ve got your plan, it’s time to do some calculations! Wherever the pipe divides, you will need tee connectors. And for every corner, you will need an elbow drip line connector. Don’t forget to use tubing with elbow connectors wherever the water supply line needs to go from ground level up onto a raised bed. Measure the total amount of irrigation pipe needed, and add a few extra meters in case of any mistakes or miscalculations!
Step 4. Installing the Raised Bed Emitter Lines
The secret to irrigating a raised garden bed is where you place the emitter lines. Install the emitter lines close to the soil surface, allowing water to drip into the soil near plant roots. The emitter tubing can either lay on the soil surface or just under or above it. The water supply line then connects to the raised bed drip irrigation layout, which requires consideration.
As we had already constructed our raised beds, we had to run the water supply line up outside of the beds. Running the line outside of the beds wasn’t a big problem. But in hindsight, the water lines could have hidden inside the raised bed frame if we had planned.
We also needed to connect multiple raised-bed gardens, meaning the water supply pipe had to run from one bed to another. At the moment, we have these lying on the surface of the paths, but eventually, I will get around to burying them to tidy up the area a bit.
Setting up this system was more fiddly than the large vegetable garden beds, with many joins, bends, and connectors! It is one of those projects that is worth the effort, though, as our kitchen garden crops look better than ever this summer.
(Although I knew drip irrigation would work even on unlevel ground, I was unsure how it would perform going up and over raised beds. But as it turns out, this isn’t a problem, provided you’ve got enough water pressure!)
Step 5. Installing Your Drip Emitters
Next, you will install the drip emitters. Each one is pushed through a small hole in the hose until it clicks into place. A bespoke tool can make this hole, or you can rig up a hole punch using a nail and a set of pliers.
Run water through the entire system for a few minutes to flush any tiny plastic particles out of the hose. Finally, push together the final connector, turn on the water, and watch those emitters spring into action!
Want to install an irrigation system to water your garden without fuss? Then check out this drip irrigation system that works perfectly for raised garden beds. It can also help water your yard, potted plants, veggie gardens, flower beds, greenhouse, or shrubs.
How Do You Keep a Raised Bed Wet?
In addition to our primary vegetable garden, I have some smaller raised beds near the house. This garden space is where I grow salad crops and cherry tomatoes in the summer, handy for picking fresh for that just-harvested flavor. They are also well stocked with culinary herbs and edible flowers, creating a beautiful all-you-can-eat display of healthy plants that are highly attractive to wildlife.
Much as I love these beds, they were always very time-consuming when watering them with a garden hose. Raised beds are the only option in this location, as there are only around 2 inches of poor-quality soil above the bedrock. We built some lovely wooden-sided beds filled with nutrient-rich compost, but they dried out far faster than our vegetable garden. In the height of summer, they would often need watering twice daily to prevent my poor lettuces from wilting in the heat! But – our raised bed irrigation system now keeps everything watered on near autopilot. It’s perfect!
How Much Water Does a Raised Garden Bed Need?
The question of how much water a raised bed needs is far more complicated than it sounds. You’ve got two potential courses of action here. Do the math and figure out exactly how much irrigation raised beds need, or take an educated guess!
How long you run your drip irrigation depends on several factors, such as the type of drip emitters, your water pressure, plant water demands, local climate conditions, and whether you have sandy or clay soil. Sandy soil in a hot climate will need far more water than clay soil in a chillier zone.
I have to admit that I’ve never calculated our raised bed watering requirements, so they may be getting more water than they need. I set the timer to water for 30 minutes three times per week in the cooler months and up to an hour per day in the peak of summer. This rule of thumb seems to work perfectly for us. It provides an abundance of healthy crops and keeps us supplied with salads all summer.
But, I did conduct the brainwork for our primary vegetable garden grid. I used this super simple drip rate guide. The drip rate guide is handy if you grow various crops with different irrigation needs, as you can set each emitter flow rate to provide precisely the correct quantity of water for each zone.
It is also vital to consider water pressure when setting up a raised bed drip irrigation system. The water source can come from a standard water faucet via pumped water or a gravity-fed water storage system such as a rain barrel. Most professional drip irrigation systems operate at a pressure range of 20-30 psi (pounds per square inch). This pressure range is far lower than the pressure of most municipal water networks, so you may need a pressure regulator to prevent damage to the hoses and emitters.
I hope you’ve enjoyed our first-hand experience setting up our raised bed irrigation network. The process was far more manageable than we expected and worth the extra cost! If you’ve got any questions or comments about setting up your drip irrigation for raised beds, I’d love to hear them!