in-ground wicking beds?

The in-ground wicking beds are an idea I’ve had for a while – a way to make wicking beds (with a water reservoir) that don’t require an above-ground bed. This is mostly because I’d already set up my garden beds with the chook run and to change them to significantly above ground isn’t practical at this point in time.

To be effective, wicking beds require:

• a container under the soil, easily refillable with water, not so easy for the soil to get into (the reservoir)
• a medium for transferring water to the soil (the wick)

A milk carton beneath the ground, stuffed with geotex then using strips of geotex/cotton fabric to wick water out, would be easily refillable, while still wicking water out to the soil instead of evaporating from the surface. Best of all, you don’t need to completely take apart and reinstall your garden bed, and you could install these in the ground.

It would probably need watering more frequently than your standard wicking bed, but should also be providing water to plants through the harsh heat of summer, only requiring filling every couple of days, and without losing water through evaporation.

Will need:

• 8x 2L plastic milk bottles
• the plastic rings from your milk
• geotextile, cut into 2” strips
• cotton fabric cut into 2” strips
• plastic straws(*)

(*) collect used straws for this, they’ll only get thrown out otherwise, and they make excellent visual markers for the location of your water wells

Process
(highly experimental, have not actually tried this yet)

1. Unscrew the lids off the milk bottles and put the lids (and the plastic rings that fix the lids) aside.
2. Cut the plastic milk bottles in half.
3. Dig a hole in the ground half again as deep as the bottom half of the milk bottle, and settle the milk bottle bottom firmly into the hole.
4. Backfill the hole around the milk bottle until the soil is about 1cm below the lip of the milk bottle.
5. Cut a rectangle of geotextile 50cm x 30cm. Fringe the geotextile along one side and roll it up.
6. Stuff the fringed geotextile into the bottom half of the plastic milk bottle with the fringe hanging out the top.
7. Cut a square of geotextile 15cm x 15cm, lay it over the milk bottle and then fit the top half of the milk bottle over the geotextile and the 'lip' of the bottom half of the milk bottle, so that the bottom half is sitting just inside the top half.
8. Backfill the hole around the top half of the milk bottle.
9. Put the milk bottle lid back on the top half of the milk bottle.

My original idea involved poking a straw through the geotex so there was some idea of where the reservoirs are when it comes time to water them. Just water over and around the straw and it would be fine! However, I am presently debating the practicality of this, the risk of soil getting into the reservoir, the difficulty in the water wells displacing the amount of soil needed for growing whatever it is that is being grown in the bed...

I may have to think about it more.