I have seen quite a few posts on wicking beds around the net of late and, well lets face it, they intrigued me.
This is just my version and there are heaps of others out there – just use Mr Google and do a search. You are bound to find a site that will explain the theory and technique probably better than I can and you will learn a whole new way of gardening as you do it.
I used the inside of an old washing machine. I have two of them and they were just the right size for an experiment and fitted nicely at the end of one of the vegetable garden beds. Whatever the container you use you will need to drill a hole/ holes about 10 cm/4 inches up from the base. This allows any excess water to drain away. It doesn’t need to be a massive hole. Ashley used a 20 mm circular drill and that worked just fine.
Now because I used washing machine tubs they have a hole in the bottom (as well as some right at the top – ignore those they aren’t important) so I put down a scrap of carpet then layered some tarpaulin then a large garbage bag then another piece of tarpaulin to stop the water draining out of the hole in the bottom of the tub.
The watering pipe is a bit of poly pipe we had sitting around. Ashley cut slits in the bottom of it so they water could drain out of it and we taped up the end using a plastic bag and plenty of electrical tape – just because there is lots of it around here.
Sit the pipe in the tub. I went for the middle as that made sense to me but I really don’t think it matters so long as it’s easy to reach.
Now comes the fun stuff. I put a layer of gravel around the pipe so that it covered all the slits in the pipe. Ashley didn’t cut any slits higher than 10 cm/4 inches and I made sure that I put gravel in a little deeper than that so it was level with the hole that was drilled in the tub to let out excess water. By having gravel and not dirt/potting mix over the hole it stops the dirt washing away.
Once the gravel is in place I started filling the tub with potting mix and compost and several good handfuls of worm castings (worms included) until it was full. I then gave it a very good water all over the soil and put plenty of water into the pipe until it started flowing out the hole at the side
As we are having a dreadful time with birds digging up everything I cut some chicken wire to fit inside the tub then pegged a square of bird netting over that to stop the birds. On one half of the tub I planted English Spinach and the other half I put in carrots. Unfortuantely I think the carrot seed might have been a bit old as not much has germinated but the English Spinach is doing wonderfully not to mention the three tomatoes that are self sown – they are now residing in posts in the green house to grow bigger. I think they came from the worm castings. I feed the worms every now and then by adding some kitchen scraps and just digging it into a spare spot in the pot.
When I can see water in the pipe then I know I don’t need to water it. Some sites I looked at used pipes running all along the bottom of their wicking beds which were fed from a filling pipe and if you were going to make larger beds than this tub that might be the way to go but for such a small area I didn’t think it was necessary. When I convert the cast iron baths I am getting to wicking beds I will still only use one piece of pipe as I think/hope that that will be all they will need.
Wicking beds work by drawing the water (wicking) up from the water reservoir at the base of the pot as the plants need it. It means the roots go down deep (a desirable thing) and use all the available water. This means stronger plants and better crops. It also means that all the water that is made available for the plants is used and not wasted in run off which in the end means less wastage. Another fantastic thing about these kinds of beds is if you wanted to sit them on a balcony or pergola and didn’t want water stains on the flooring then they are the way to go . You could use a sealed tub – I have seen heaps of plastic decorative pots in the garden centres that would look stylish and allow you to have a garden without the bother of water stains.