Advertisement
Home Garden Gardening

How to make a wicking garden bed

Let your clever garden water itself, from below!
Loading the player...

WATCH: Charlie Albone shows you how to build a wicking bed 

Advertisement

Traditional raised garden beds can be great, but they may require large amounts of soil to refill as their levels drop when the soil breaks down. Wicking beds are a fantastic alternative that look similar but require less watering and far less soil.

This is because a wicking garden bed is designed with a water reservoir at the bottom, which feeds the plants above. This helps you save time and water. Plus, wicking beds are usually super simple to put together.

How does wicking work?

Wicking is the movement of water by ‘capillary action’, where water from a reservoir below the soil is drawn up and evenly distributed through the soil to the plants’ roots. Excess water goes through an overflow pipe, which ensures the soil doesn’t flood and doesn’t drown the roots.

Wicking bed in back yard
The final result! (Credit: Brent Wilson)
Advertisement

Advantages of wicking garden beds

  • As water comes from below, there’s no surface water loss via evaporation.
  • Watering from above can cause fungal damage to foliage.
  • Roots that need the water get it, not the top bits.
  • A constant water supply means stronger, healthier roots – think of plump, tasty carrots and beetroot.
  • As the plant is always fully hydrated, leaves don’t get sunburnt during heat waves.
Wicking bed diagram
How wicking beds work: the important action takes place under the surface.

How to build a wicking garden bed

Gather your supplies

You’ll also need:

Here’s how to make a wicking bed

Step 1

Position your raised garden bed in full sun and on a level surface.

Advertisement

Step 2

Charlie Albone lining raised garden bed
Step 2 (Credit: Brent Wilson)

Line bed with pond liner, ensuring there are no holes or gaps along edges and corners. Hold in position with bulldog clips.

Step 3

Advertisement
Add scoria to garden bed
Step 3 (Credit: Brent Wilson)

Add 25mm of scoria to base of the bed.

Step 4

Coil pipe in garden bed
Step 4 (Credit: Brent Wilson)
Advertisement

Coil agricultural (ag) pipe around scoria bed, with cap end sitting on rim of garden bed. Cover pipe with more scoria

Step 5

Drill hole in side of garden bed
Step 5 (Credit: Brent Wilson)

Drill 20mm hole into side of garden bed, just above scoria.

Advertisement

Step 6

Intsall overflow tap parts
Step 6 (Credit: Brent Wilson)

Install overflow tap parts in drilled hole and seal with silicone sealant.

Step 7

Advertisement
Trim liner
Step 7 (Credit: Brent Wilson)

Trim liner to just above scoria.

Step 8

Cut opening for ag pipe
Step 8 (Credit: Brent Wilson)
Advertisement

Cover scoria with geotextile fabric. Cut opening for ag pipe and trim fabric to fit.

Step 9

Fill garden bed with potting mix
Step 9 (Credit: Brent Wilson)

Fill garden bed with quality potting mix.

Advertisement

Step 10

Plant seedlings
Step 10 (Credit: Brent Wilson)

Plant seedlings, cover mix with sugar cane mulch and water well.

Step 11

Advertisement
Fill pipe with water after a couple of weeks
Step 11 (Credit: Brent Wilson)

After a couple of weeks when roots are established, fill pipe with water. Put cap on to prevent mosquitoes breeding.

What are the disadvantages of wicking beds?

If you let the overflow water drain into the ground, you’re wasting water. If you let the overflow water drain into a bucket, empty it immediately into other parts of your garden or you’ll attract mosquitoes.

What do you fill a wicking bed with?

Line the base of a raised garden bed with pool liner then fill with scoria or pebbles – not  road base as there is too much fine material in it – into which you place an ag pipe, cover with geotextile fabric then fill with quality potting mix. The ag pipe protrudes through the potting mix as that’s where you add the water for the underground reservoir.

Advertisement

How deep do wicking beds need to be?

As deep as you like, but the soil/potting mix should be about 30cm deep.

What is the best soil for wicking beds in Australia?

Only use quality potting mix. Soil needs microbial activity such as worms, beetles and beneficial organisms such as fungi and bacteria to keep it aerated. Without this underground activity the soil collapses and nothing will grow there.

Potting mix needs to replaced every couple of years as it breaks down and collapses too. You can toss old potting mix onto garden beds where it breaks down further.

Top 6 raised garden beds

1. Slimline garden bed, Kingspan, $705

Advertisement
kingspan raised garden bed

This Kingspan slimline raised garden bed is made from food-grade polymer-coated steel that’s specifically designed for long-lasting, durable garden beds.

Key features:

  • Internal, food-grade liner
  • Suitable for growing herbs, fruit or vegetables
  • Five-year structural warranty

SHOP NOW

Advertisement

2. Gordo galvanised steel raised garden bed, from $69, Temple & Webster

Temple and Webster raised garden bed

This stylish and practical garden bed is made from quality galvanised steel with an epoxy paint finish to help ensure longevity.

Key features:

Advertisement
  • Rounded and rubber-capped edges
  • Inward-facing screw reinforcements for durability and safety
  • 12-month product warranty

SHOP NOW

3. 110cm Ergo Hex raised garden beds (set of 2), $219, Temple & Webster

Hex raised garden beds

This unique hexagonal design looks great and can also help you save space by fitting into corners or allowing for stackable beds.

Advertisement

Key features:

  • Ergonomic and space-saving design
  • Made from weather-resistant polypropylene plastic
  • Five-year warranty

SHOP NOW

4. Potey raised garden bed with greenhouse, $117.11, Amazon.

Greenhouse raised garden bed
Advertisement

This galvanised raised garden bed also comes with a greenhouse frame and two covers so you can keep hungry animals away.

Key features:

  • Two greenhouse covers for different seasons
  • Soil ventilation holes
  • Designed for durability

SHOP NOW

5. VidaXL raised garden bed, $76.99, Amazon

Advertisement
Rectangular raised garden bed

This galvanised steel garden raised bed is weather-resistant and easy to assemble, so you could have flowers or other plants thriving in no time.

Key features:

  • Made from heavy-duty galvanised steel
  • Provides ample space for plants, vegetables, herbs and flowers
  • Open bottom design

SHOP NOW

Advertisement

6. Greenfingers round garden bed planter, $57.95 Amazon

Greenfingers round garden bed.

This round, galvanised steel garden bed is stylish, affordable and suitable for both small and large gardens.

Key features:

Advertisement
  • Made of quality galvanised steel
  • Latch design for easy assembly
  • 0.5mm thickness for extra stability

SHOP NOW

For more great gardening stories, check out the latest issue of Better Homes and Gardens magazine.

You might also like:

Charlie Albone’s guide to creating raised garden beds

Advertisement
0

What is the wicking bed method?

How to make wicking beds with old wine barrels

How to fill a raised garden bed, cheap

Advertisement

Related stories


Advertisement