By command of Her Royal Highness, our friend Tia Maria:
Say you don't have a lot of land, or none, for that matter? Well, no problem! Just about anyone anywhere can have a few self watering buckets to grow something in. If you have a porch or patio attached to your condo or some place that gets good sunlight somewhere, you can grow at least some herbs. In this post I'll take you through how to build a really simple self watering contraption that we have had very good luck with in our little suburban yard. All you need are two five gallon buckets (check with local restaurants, we get our buckets free from a pub, former pickle buckets), a length of 1" diameter (approx) pvc, some 2-3" pvc, a drill and saw, some way to maky bigger holes (I have used keyhole saws, rotary cutters, utility knives, or easiest: hole saws on a drill) and some zip ties. Let's get it going:
Take your first bucket and drill a whole mess of holes in the bottom. This provides both drainage and a way for the soil and roots to get the air they need.
After that, we need some way to get the water to the plants. The water will be in a reservoir made by the second bucket to come later. It will sit under the one you've drilled. We need a wick, so measure a piece of the wide pvc (2-3" diameter) so that it will reach the bottom of your second bucket when they are stacked. In our case, that's about 4". Cut that bit of pipe and fill it full of holes with the drill. Make a big hole in the middle of the bucket a little smaller than the inside of the PVC wick.
Then, with zip ties, and a few strategically placed holes, fix it to the bottom of your holey bucket.
Good. Now we need a way to get the water into the reservoir. That will be done through the use of the thin pvc you gathered. Drill or cut a hole that is a bit bigger than the outer diameter of the pipe on the rim of the bucket, then cut the pipe so that it's long enough to go to the bottom of the two stacked buckets and stick a bit above the top one's rim. A little angle trim will let the water out into the reservoir when you're filling.
cutting the hole:
cutting the angle into the fill pipe (note, you can drill it, too.)
With that done, a couple of holes near the top of the holey bucket can be used to secure the fill pipe with another zip tie. Then, just put the finished holey bucket into another bucket. Just below where the inner bucket meets the outer bucket, you need to drill a few holes so that excess water can drain (you don't want to drown the poor plants, do you?).
After you've done all that, you have a useable self watering bucket to grow almost anything in. Stack it all up, fill it with potting mix (N.B. make sure that the pvc wick is full of dirt so that some soil is down in the reservoir to bring water up to the plants) and plant away!
You can use the lid of the planter (with a hole for the fill pipe and a hole for the plant) as a substitute for mulch and weedcloth, but we usually don't bother with this step.