A long weekend gives you a good opportunity to get stuck into those jobs that take just a little bit longer than a normal weekend will allow. Last weekend I was able to finish off a job which had been in my thoughts for quite a while – a wicking garden bed. I know we have had rain lately but summer is ‘i cumen in’ so I really want some help in keeping those plants growing with a bit less watering labour on my part. Not to mention keeping things alive while you nip off for a week down the coast.
I’d heard about wicking beds earlier this year, a garden bed that actually watered itself. The basic principle is easy enough. You build a garden bed over a water reservoir and the capillary action enables the water from the reservoir to infiltrate the soil keeping it moister longer and reducing the need for watering.
You may have seen the wicking beds that Costa installed at the Tembeleski family home (in the last season of Costa’s Garden Odyssey). You can check out the video if you missed the show.
Costa’s version looks great and is very straightforward but unfortunately not a cheap option. As Costa commented “All up it cost about $875 to build and plant out one of the three garden beds”.
Thankfully there is a less expensive option. In fact you can go straight back to the source of Costa’s idea by visiting Colin Austin’s website where you can find all the information you need to get a wicking bed happening.
What you need:
- Concrete blocks or timber to build the walls of the reservoir
- Flexible plastic pipe
- Thick plastic for lining
- Woodchips for ‘fill’ in the reservoir
- Shadecloth to form the ‘walls’ of the upper bed and a bit extra to make a permeable barrier between the soil and the woodchip
- Stakes to fix the shadecloth onto
- Soil to fill your upper bed
Now for the manual labour!
As you can see from the photos I opted to build the water reservoir of my bed from concrete blocks, some we already had and a few more I needed to buy. There are plenty of options for the building the walls of the reservoir such as scrap timber or metal sheeting. I chose the blocks because after our recent encounter with termites I wanted to avoid anything that would encourage their ongoing presence in my garden.
Having levelled the base of the reservoir – you do need to get this bit right – place your plastic lining inside the walls, Allow a bit extra lining all around. Next take your piece of flexible pipe, again we had some corrugated pipe lying around, and drill some holes along one side (if it doesn’t have some already). This is the access point for your water so make sure at least one end of the pipe is sticking up above the complete height of your bed! With the holes in the pipe facing the bottom put it inside the reservoir. This is to help keep the holes free of debris. You may need to hold the pipe down with a brick or a rock until you can get your fill in place.
Pre-drill your holes in your stakes (we used thick hardwood garden stakes) to make fixing the shadecloth on them a bit easier. Hammer the stakes in around your reservoir – making sure you don’t hammer them through your lining! Fix your shadecloth onto the stakes. Make sure you allow a bit more slack around the corners to avoid ripping it. Put shadecloth inside the lining.
PS I didn’t do it in this order and just made extra work for myself.
Fill the reservoir up with woodchips and level them out. I also filled the reservoir with water at this stage to check that the water was coming evenly up all over the bed.
Place your spare bit of shadecloth over the woodchip to stop too much dirt getting into the reservoir. Fill your bed up to the required height – between 20-30 cms – with soil. I used some garden soil mixed with compost and some mushroom compost.
Et voila, your bed is ready to plant.