Irrigation for Raised Bed Gardening

This past summer my husband and I built raised beds in an effort to eat more organic, local veggies (I mean how much more local can you get than your backyard?). The first step was creating the frames for the beds, second step was the soil (more on that in another post), and the last step was planting our seeds. Next came watering. My type A (capitalized for emphasis) husband became determined to find a way to create an easy watering system. For weeks he watched hours of YouTube videos and read long boring articles online. Since he spent so many hours researching we thought we would share our solution. ** Note: we are NOT expert gardeners, but are sharing our gardening experience with others on a similar journey.

The principal is simple: water flowing from larger pipes to smaller pipes with the versatility to turn on or off any combination of beds and/or individual rows. The first step was to analyze and study how each plant needed to be watered manually. While doing so we concluded that there are three basic watering techniques required that we would need to simulate.

Mist

Soak

Spray

The first of many failed attempts started with soaker hoses (see image below). This was an epic fail. My husband almost got voted off the island for this one. We found that this effort watered all of the areas we didn’t need and didn’t water what we DID need. It was a waste of water and time.

In turning to YouTube we found other people had luck with PVC pipes, refrigerator supply lines, milk jugs, and other various things. Each of these ideas were assimilated into a method that met our project requirements: which were ease of use, efficiency of time each day, and maximization of water per square foot. Quickly it became apparent that the smallest hole possible alternating 10 degrees in both directions from absolute center running lengthwise down the ½ inch pipe would yield the highest pressure output. Using ¾ inch trunk line with reducing T joints the output pressure was further maximized across 6 or more rows. Since each pipe can serve two rows (one in each direction of absolute center) this system can easily sustain 12 or more rows with a standard house garden hose without a pump. No glue is needed. This also allows the system to be dismantled and reconfigured for multiple garden layouts.

Reason why we didn’t go with a fancy expensive solution:

Other systems available that cost many hundreds of dollars more have specialized pipes, fittings, and filters that can clog up and stop working. With the PVC pipe and 1/16 of an inch holes, clogging will rarely, if ever be a problem. And if clogging does become a problem, you are only out a few dollars or you can shake out the sediment.

Parts list:

¾ inch PVC pipe (buy in 10 ft. sections for 10 ft long raised beds, 8 ft. for 8 ft raised beds, etc) You will only need one of these per bed.

½ inch PVC pipe (three per bed for a 10 ft bed for an example giving you approx. six pipes watering 12 rows)

(six) reducing T joints (reduces from ¾ inch to ½ inch)

 

 

 

 

(one) ¾ inch 90 degree elbow joint

 

 

 

 

 (one) ¾ inch shut off valve (value added benefit of giving you variable pressure)

 

 

 

 

(one) ¾ inch T joint for connecting the source line between raised beds

 

 

 

 

(one) threaded PVC connector for hose connection

 

(one) 3/4 inch end cap
(six) 1/2 inch end caps

Tools Needed:

• drill
• 1/16 inch drill bit (buy several because they break easily)
• pipe cutter or saw

Time to create:

It will probably take you 4 -5 hours to create the irrigation for one bed. If you experiment it make take a few days. Once we got the system down the final bed only took a couple of hours. The experimentation is what takes so long.

Considerations:

The design is flexible to have greenhouses to be built on top of the irrigation system.

Areas for improvement:

Rain barrel implementation
Auto timer that switches between beds automatically drawing water from rain barrel supply.

So long are the days we have to lug the long garden hose around and spray each bed manually. YAHOO! Snaps for my husband for finding an irrigation solution for our raised bed garden.

This post was co-written with my husband; a designer, computer programmer and teacher by day and garden efficiency engineer by night. Here is an  in-depth video he created about the system.

 If you have a garden, how do you handle watering?