Wicking Worm Beds

I mentioned in the New Design posts the fact that most of my vegetable beds have been made as raised Wicking Worm Beds.

This is a link to many posts about Wicking Worm Beds on my garden blog.

So How Do These Beds Work?

Above is a simplified diagram of an in-ground wicking bed. Click on the photo to enlarge it!

Basically, water is stored at the bottom of the bed and 'wicks' it's way up through the growing medium to saturate the roots of the plants...as it dries oxygen is pulled into this medium allowing the plant's roots to breathe. The plant roots do not grow in the wet 'pool' area.

The way I've made these is by digging out about 10cms into the earth. This area is then lined with a plastic sheet including the sides so that water can be retained in the below ground 'pool' area.

In this area I have used sand as the medium to hold the water...sand seems to work for me. Others have used bagasse and I did try straw in the wicking boxes but found it broke down very quickly.

This area needs some way for the water to reach it...usually this is via some slotted drainage pipe but there are other ways to get the water down to the bottom of the beds. In my first bed I used 4 litre juice bottles and it worked OK.

The drainage pipe can have poly downpipe added with connectors and either needs a cap on the end or you can just have both the ends of the pipe exposed to enable you to fill it with water from either end.

Now use something to hold the raised growing area in...I've used cut down water tanks and galv iron sheets joined in a box shape. I have also tried mesh and one lined with newspaper but these galv ones look neater.

Before putting the 'box' on the top you need to allow for a drainage hole or gap...some way of allowing excess water to drain away...it's also useful to know when the beds have had enough water added.


The growing medium needs to be fairly rich in compost/humus. The best material for the wicking action is pure compost worm castings...

I mix these with compost and add a layer of new compost on the top. A good mulch layer is needed on the very top to stop evaporation. Also it keeps the area cool for the Worms that live there...

With the worms added, I covered the whole bed with some clean underfelt...put holes in the bucket for worm feeding (it's now under the felt) and they will sit until the time is right for spring planting in October.


Links:
Waterright Site
Wicking Box Gardens
Wicking Boxes in the Heat
Watering Setup
April Update