The concept behind self-watering planters couldn’t be simpler; the idea being that a wick draws moisture up into the earth from a reservoir inside the planter. Armed with that knowledge, any DIY home enthusiast can set about making their own self watering planters.
To make your own self watering planter you must have two waterproof pots, one of which will sit inside the other; any old plastics pots will do as they can be put inside a more decorative/aesthetically pleasing planter pot visible to everyone. Alternatively the outer pot could be one that you’ve painted or decorated yourself, or it might even be a decorative pot you’ve previously bought for the garden.
Anyway, returning to the two pots that will act as the self watering planter – between the inner and outer ones needs to be a gap of 1 to 2 inches, we can then use that gap to get extra air flowing around the inner pot. So, the outer pot will be the water reservoir, whilst the inner one will contain the earth and plants.
Building a Double Pot Self Watering Planter
The inner pot needs to sit on something inside the outer pot, to raise it off the floor of the water reservoir. An upturned pond basket is ideal for this; alternatively you could possibly use something similar to an upturned ice cream tub. However, whatever you use it must look like a mesh – have lots of holes in it – as it will be sitting in water and you don’t want it trying to float.
Whatever you use as the shelf, on the outer pot, having noted the height of the shelf, drill a couple of holes slightly above that height. These will act as drainage holes if the water level inside the outer, water reservoir, pot rises too much.
You now need a couple of lengths of plastic pipe; ideally one about 1 inch in diameter and the other at least 4 inches in diameter. The thinner of these two pipes will be used to fill the water reservoir. It needs to be long enough to be above the level of earth in the inner pot but to also reach the floor of the outer pot.
Drill a hole through the inner pot, probably near its side, so that the pipe will just pass through it and another hole through the shelf, aligned with the first one. Drill a few holes at the bottom of the pipe to help water escape from it.
The wider diameter pipe will be the wick, which needs to be long enough to not quite sit on the floor of the outer pot – but it should reach about one third of the way up the inner pot.
Drill holes through the center of the inner pot and the shelf to accommodate this wider pipe and again drill holes in it below the level of the shelf. Finally drill some holes in the wall of the inner pot, air flow around these holes will help aerate the earth and promote strong root growth.
Push the two pipes through their respective holes in the inner pot and the shelf. Using the narrower pipe; pour water down it, until it starts to come out of the overflow holes. Add the earth to the inner planter; don’t worry that the wider pipe immediately fills with earth, this is the wick.
However, don’t let any earth go down the pipe for topping up the water reservoir. Moisture will be drawn up into the earth through the wick and you can now add the plants. After a day or two replenish the water reservoir, after that it should only need checking every few days depending on the weather conditions.
Photo by randomidea, Creative Commons Attribution License