Wicking, Self-Watering, Subterranean, Sub-irrigated Planters or Containers
I have been experimenting with wicking planters (Self Watering, Subterranean, Sub-irrigated, or whatever else they might be called).
I have had some store bought containers which are supposedly self-watering but never seemed to work in that way, even though they really are one of my favorite containers as far as size and shape goes when just used as normal containers watered from above.
My experience with these planters had rather tarnished my view on self-watering containers and I had never really pursued their use any more. A few months back I went to a workshop run by the local council (shire) about compost making and using wicking beds or planters and got all enthused!
I purchased four plastic 60 liter bins from Bunnings (our local hardware store). They were reduced in price from $10 to $2.50 because they had no lids which was fine by me…I don’t mind a bargain!
I placed some old plastic plant pots upside down in the bottom which were about one third the height of the container. I drilled a hole in the end of the container just above the height of the pots. This is the overflow hole so that water doesn’t sit in the root zone. All the area below the hole is the water reservoir.
I placed a length of plastic pipe upright in one corner on the opposite end to where the overflow pipe is. The pipe sticks up above the sides of the container. I cut the pipe on an angle on the bottom so that it doesn’t end up being sealed against the bottom of the container and not allow the water to fill the reservoir. This is the filling pipe to fill the reservoir.
In some of the containers I filled them with sand in between the gaps in the pots and others I put old tea shirts, rags etc. to act as wicks to bring the water up. Then I placed a layer of old carpet or felty material on top. This absorbs water and stays moist as well as stopping the growing mix from falling down into the reservoir.
I placed my containers in their final positions before I filled them with my compost as they would be heavy to move by myself once they were filled.
Once I had filled the containers I planted them and gave the plants a good watering in to wet the compost and then I poured water in the filling pipe with the hose until it started to run out the overflow hole (that means the reservoir is full).
I have placed fine gauze sort of material over the top of the filler pipes held in place with bands made from thin elastic cord (rubber bands just disintegrated in no time) to keep the mosquitoes out of the water reservoir.
I sowed lettuce and mizuna in one, planted a Zucchini (summer squash) in another, and bell peppers in another. In the fourth one I planted spinach that I thinned from my trough and I also sowed a few beetroot and rocket (arugula) in the end.
Now that I am tuned in to wicking containers when my husband was discarding three little wheelie bins that he had been using for storage of short bits of steel etc. in his shed and no longer needed I immediately had other ideas for them! They had been retrieved from the roadside when we had bulk verge collections so are being recycled yet again. Pink, blue and lime green they have added a bit of color to the garden too!
I did the same with them putting old upturned pots in the bottom third and using old rags stuffed in between as wicking material.
I again covered this with old carpet. I put a filler pipe in one corner and drilled an overflow hole on the other side at the height of the carpet layer or slightly above.
I planted a tomato in one, a zucchini in another and climbing beans in the other. I put stakes in to make a tepee for the beans and will have to sort something for the tomato. I think with the Zucchini I will just let it spill over the side as there is plenty of room for it to grow wherever it wants.
Next I found some empty 20 liter (I think) buckets that I could utilize, all previously recycled from the roadside too. Two already had holes in the bottom so were partly prepared. I took a bit of a different approach for these containers. I stacked one inside the other so that the bottom one formed the reservoir. I like this idea for the buckets as it means you get to use the full capacity of the container for planting rather than just two thirds of it. Some people use a lid inside to separate the planting part from the reservoir but this means only using two thirds of it as in my other containers.
I drilled an overflow hole in the side of the reservoir bucket at the level where the top bucket goes down into the reservoir. I drilled holes in the bottom of the top bucket and also cut a bigger hole in the center with a hole saw which was the size of a container or pot that I was going to sit in it and fill with sand and use as my wick as it protrudes down in to the reservoir. I drilled lots of wee holes all over the little container so that it can wick up the water from the reservoir. I also made a hole to poke my filler pipe thru into the reservoir in one side.
In the other bucket I didn’t use a small container as a wick but found some old webbing to use instead. I looped the webbing back and forwards in a bundle that was the length of the height of the reservoir plus a bit more. I drilled a hole in the center of the bottom of the top bucket which was the size of my bundle of webbing and then poked thru enough of the webbing until it reached the bottom of the reservoir. I put a bit of plastic sort of rod thru the top loops so that the webbing couldn’t pull thru into the bottom. I had already lined the bottom of the top bucket with some of the thick felty material so brought the webbing up thru that too. The material went quite a way up the sides of the bucket so should also help with wicking.
I planted a tomato in one bucket and a cucumber in the other.
I used the tops of my broad beans that I cut back as mulch for my bucket containers. I had some other stuff which was originally old roots from a very pot bound old ornamental agave plant that I had soaking/rotting in a bucket of water for months but hadn’t really broken down. It works ideal for mulch in the wheelie bins. I have yet to find something to mulch my bins.
So far I am very pleased with my wicking containers. They are staying moist and the plants are flourishing. My other ordinary pots need watering almost every day now that we are getting hot days. It seems as though I only need to fill the reservoirs once a week; I have taken note of when I filled them last so am interested to see how long before I need to top them up. That is so much better than watering every day and some of it running out the bottom of the container!
I am now on the lookout for more suitable buckets as I have two tomato plants in small pots waiting for a final home! Hopefully the local bakery will have one for me today or tomorrow so that will be a start.