How To Build A Self-Wicking Raised Garden Bed

Building a self-wicking bed is easy and straight forward. 

MATERIALS:

57 or 77 gallon storage tub from a big box store

5 feet of 2" diameter pvc pipe

2" pvc 90 degree elbow

2" PVC Pipe Cap

3/8" Drain fitting

6-8, 0.5 cu. ft. bagged red landscape lava rock

4ft x 50ft roll of heavy duty landscape fabric

Soil - SEE BLOG ON MAKING YOUR OWN SOIL

HOW TO ASSEMBLE:

  1. Drill a 3/8" hole 5 inches up from the bottom of the tub and centered on one end. (this is your overflow for the tub) INSERT drain fitting and secure on the inside washer and nut.
  2. Place the tub in its PERMENANT location.
  3. Cut the 5ft pvc pipe into a 3ft and 2ft section. 
  4. Drill alternating holes down either side of the 3ft piece of pipe.
  5. Connect the 2ft piece of pipe and the 3ft piece of pipe with the 90degree elbow (Use PVC glue to connect). You should have an "L" shape pipe
  6. Place the 3ft piece with drilled holes in the bottom of the tub. The vertical 2ft piece will be your watering spout. The watering spout should be at the OPPOSITE end from the drain plug
  7. Pour your Lava Rock over the 3ft piece of pipe until it fills the bottom 4-5 inches of the tub.
  8. Place the landscape fabric over the rocks and then run it up the inside walls and ends of the tub. This keeps the soil out of your rocks and water.
  9. Fill your tub with soil by placing on top of the landscape fabric - SEE HOW TO MAKE YOUR OWN SOIL BLOG POST
  10. Use the downspout to fill your tub with water until it starts to flow out the drain fitting.
  11. Cap your pipe to keep bugs and trash out.

For the initial watering also wet the soil from the top. After a good soaking, you will not need to water except through the downspout. 

Now you are ready to place your plants in the raised bed. Through wicking action, your plants will take up only as much water as they need. About once per week fill the bottom of the tub with water until it flows out the drain fitting. That's it!