Check out below to see how you can build your own self watering container garden. It may not be easy but the payoff will be incredible!

Here’s how to do it

1. Construct the wooden boxes. One advantage of using wood is that you can create boxes to fit the size of the space.  You can preserve wood with Osmo wood oil or linseed oil, and line the wooden boxes with plastic to slow down the rotting. Be aware that the weight of a large wooden box plus soil can be considerable (I placed these boxes on top of a load bearing wall to hold their weight).
This shows the simple wooden boxes with the plastic reservoirs in the bottom. The right hand box also has it's ‘feet' cut, ready to attach to the corrugated plastic.
This shows the simple wooden boxes with the plastic reservoirs in the bottom. The right hand box also has it’s ‘feet’ cut – grey 110mm drainage pipe. The corrugated plastic false bottom will rest on top of these feet.

2. Find a plastic container that fits inside the box to act as a reservoir (the green boxes above). This reservoir needs to be 15cm – 20cm (6 – 8 inches) high – you can use a hacksaw or jigsaw to cut the top off if it’s too tall (I used old 50 litre recycling boxes, and cut the top off). The reservoir does not have to be the exact size of the wooden box – just large enough to hold a reasonable supply of water. If the plastic box has holes in the bottom (most recycling boxes do, unfortunately), you’ll need to make it waterproof. The easiest way I found is to block them up with a silicone sealant.

3. Drill a 1cm diameter hole about 12 cm above the bottom of each plastic reservoir. This is an overflow hole and prevents overwatering of your plants.

4. Drill lots of holes in the 110mm (4 inch) drainage pipe and then cut it into 15cm (6 inch) lengths (you want 20 – 30 holes in each 6 inch length). You can see the cut bits of pipe in the top right hand box in the picture above. These bits of pipe will next be attached to the false bottom of the container, like feet (you can see them attached, below). Filled with soil they’ll sit in the water of the reservoir and wick the water up into the main part of the container.  The number of ‘feet’ you need in each container depends on its surface area. Garden Rooftops say that the surface area of the feet should be 5 – 15% of the surface area of the container. More than than this and your soil may get water logged, less and it may dry out. For these 60cm x 60cm containers, I calculated that four 110cm diameter feet would be about right.
The corrugated plastic is cut to fit into the box and sits on top of the reservoir. I added a wooden ledge to hold it secure at the sides. You can also see the ‘feet’ attached with ring ties. The surface area of these feet should make up 5 – 15% of the total surface area.

Go to Vertical Veg to check on the follow-up instructions (5 through 9) from the above list.

While the world is changing around us there will always be plants that need irrigation. And while the methods might change, from hose to sprinkler to self-watering, the fact that vegetable need water to grow will not stop.

We say make it effortless on yourself. Learn from the article above and on the link. Gardening just got a little easier!