Wicking beds: Good, Better, Best

Wicking beds are commonly used in the permaculture movement, and are a fabulous way to grow healthy plants with bottom watering.  When plant roots reach down for water, they grow deeper and thicker, which means more nutrient gathering and healthier top-growth.

Even better, wicking beds allow you to go away for the weekend in the summer without worrying about your vegetables or flowers.

grow tomatoes in Calgary

A wicking bed showing healthy tomato plants about to bloom.

Wicking beds are created using a container with a water-proof bottom.  This may need to be created using poly-plastic (cheap, but breaks down) or pond liner (expensive, but lasts.)  A PVC pipe with elbow is put into the bed vertically, with a connecting PVC (with holes drilled in it)  running horizontally across the very bottom of the bed.  The vertical pipe should stick up above the level of the soil, and can be capped for more water retention.

wicking bed design

Diagram of a simple wicking bed.

Once the PVC pipes are in place, a layer of gravel is added. (Make sure the wicking bed is in it’s final spot before you add the gravel.)  This can be from 4-12 inches deep depending on the depth of the container.  Once the gravel is levelled, a double layer of landscape fabric is added to separate the soil from the gravel.  At this height, several drainage holes should be added to allow for overflow and prevent the soil from becoming water-logged.

On top of that, a rich compost mix soil is added, to a depth of 12-18 inches.  (Fill the soil to the rim of the container).  New plants will need some top watering until their roots are deep enough to reach the wicking mat.  The reservoir is kept full by adding water through the PVC pipe until it runs out the over-flow holes.

They are fairly simple to create, and there are many ways you can incorporate this concept.  Which one is best?

Good: The plastic storage tub wicking bed

bottom watering, container vegetable gardening

Create a wicking bed out of a plastic storage container.

 

  • A great inexpensive way to try a wicking bed
  • If you move, it can come with you
  • It can be re-purposed to store other things
  • Drawbacks: It will be very small, so not many vegetables can be grown
  • It is made with plastic, and leaching is a concern

Better: The Costco raised garden

Here is a pre-made wicking bed available at Costco.

Here is a pre-made wicking bed available at Costco.

  • A waist height container allows for easy gardening without hurting your back
  • This is likely the best option for people with mobility issues
  • The garden can be moved
  • Drawbacks:  It’s pricy
  • Again, it is made with plastic, so leaching is a concern
  • The gardening area is not very big, so not many vegetables can be grown
  • The reservoir is also shallow, so it may not hold enough water for a long period away.

Best: The built in cedar wicking bed

gardening in Calgary

A built in cedar wicking bed is attractive and functional.

  • Attractive
  • Can be made to any size, and customized to fit the available space
  • No plastic, so leaching into the soil is not as likely
  • Rain barrel overflow can be directed into the PVC pipe
  • Drawbacks: More expensive
  • Woodworking skills required
  • Best for a permanent garden
wicking bed, cedar planter

Cedar wicking bed with built in lattice trellis.

water restrictions, bottom watering

The rain barrel overflow is directed into the wicking bed.

Have you thought of using a wicking bed to grow vegetables or flowers?  Do you worry about going away in the summer?

Posted Saturday, March 5th, 2016 under Good, Better, Best, Quick tips, Uncategorized.

4 comments

  1. Lea Randall says:

    Hi Kate,
    I love this project and I want to give it a try. I was wondering how many holes I should drill in the pvc pipe? Should it be well perforated all around or will a single line of holes work?

    • katekennedy says:

      Hi Lea,
      I think the benefit to having more than a single row of holes if that if some debris washes into the pipe, the holes may become clogged and water flow will slow. Many people cap the vertical PVC pipe to prevent evaporation and keep debris out of the gravel bed, so that is another option.
      Kate

  2. I have a cedar planter similar to the one in your photo. If I were to turn it into a wicking planter, should I line it completely with the pool liner first? That is, sides and bottom?

    • katekennedy says:

      Hi Leslie,
      You wouldn’t need to line all the way up the sides, but the bottom and the lower sides up to where you would drill you overflow holes. Basically: where the gravel is needs to be water-tight, and where the soil is should not be water-tight. I hope that helps!

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