Watering is a fact of gardening. Plants need water and, unless the weather is rainier than you want it to be, you have to give it to them.
You can do this with a system of hoses and pipes, in which case your effort stops being watering and starts being irrigation. Or you can stand next to the garden with a hose, which is what we end up doing most of the time. The bigger your garden, the longer it takes. Last year, when it took a good half hour to water the plants, I started to see the appeal of self-watering containers.
Yesterday, I made two of them, and I’m going to tell you how in this, one of my occasional series of bona fide how-to posts. But now that I have you on the edge of your seat, I’m going to deliver the death-blow to your nascent enthusiasm.
Here it is: my self-watering containers are another in my series of experiments in hydroponics.
Last week, I told you about the gravity-feed system we set up for our kale, and it went over like a lead balloon. Instead of appreciative comments about how creative and interesting our system was, my post was met with stony silence. A couple of you left remarks along the line of, “well, if you really must …” The rest of you must have been operating on the maxim that, if you have nothing nice to say, say nothing at all. That, or you were all washing your hair that day.
So now I’m asking – what’s wrong with hydroponics? Is it that it’s not organic? Is it that it’s more science than nature? I think it’s the coolest thing since sliced bread, but I’ve always been more scientist than naturalist.
Talk to me.
And now, my self-watering containers.
“Self-watering” isn’t really accurate. You still have to do the watering. But you can give your plant several days’ worth of water at one go, and the container enables the plant to soak it up in its own good time.
There are as many ways to assemble self-watering containers as there are discarded containers, but the basic elements are the same. You need a reservoir of water, a way for the plant to access the reservoir, and way to refill the reservoir.
I read a number of methods, and then pretty much followed an excellent set of instructions from Mother Earth News. Here’s my version.
You’ll need two 5-gallon compound buckets that nest (the outer will be the reservoir, the inner will hold the soil and plant), a one-quart deli or yogurt container, and a pipe about an inch in diameter (I used PVC) long enough to reach from the bottom of the reservoir to the top of the soil. Two feet does nicely.
That’s it: two buckets, a yogurt container, and a pipe. The rest is tools.
Mainly, you need a drill. Everything’s going to need holes. You’ll also need a knife or hacksaw for the holes that are too big to drill. Got those? Here goes.
1. Figure out how deep your reservoir is by placing one bucket inside the other. (So the pictures make sense, I’m using the orange bucket as the interior, and the white as the exterior.) Cut down your yogurt container so it’s about a half-inch deeper than the reservoir depth. This is going to be your wicking chamber. It’s going to stick out the bottom of your interior bucket, and will contain the soil that’s in contact with the water.
2. Trace a circle the size of the cut-down yogurt container in the center of the bottom of the interior bucket, and cut the circle out. It doesn’t have to be a perfect fit.
3. Trace a second circle on the bottom of your interior bucket (near the edge), this one the size of the pipe you’ll be using to fill the reservoir, and cut that out. If you have one of those drill bits they use for cutting doorknob holes, that works well. Again, it doesn’t have to be a perfect fit.
4. You now have two big holes in the bottom of your interior bucket. Using a ¼-inch drill bit (or anything remotely resembling it – size isn’t crucial), drill about a dozen other holes in the bottom of the bucket. These are for ventilation.
5. Punch many holes in your yogurt container. These are the holes through which water will wick into the soil. They should be in the ¼-inch range. I used an awl, and then made the holes a little bigger with the drill.
6. Cut the end of the pipe at an angle, so it doesn’t sit flush on the bottom of the reservoir (which would make filling it difficult).
7. Assemble! Put the interior bucket in the exterior bucket, put the yogurt container through the hole in the center, and the pipe through the appropriate hole.
8. The last step is to drill a small hole in the exterior bucket, just below the bottom of the interior bucket (if you hold the assembly up to the light, you can see where that is). This is so that you can see when the reservoir is full – the water will start dribbling out the hole.
That’s all there is to it. I built two of these in about 45 minutes.
Materials for both containers cost me about five dollars – two Home Depot buckets, at $2.50 each. My friend Rick gave me the other two buckets, and we have lots of spare PVC lying around because we use it in our oystering. I go through lots of Trader Joe’s goat yogurt, and have a collection of the containers. (I had to empty some fermented beans out of one of them; it’s a measure of my housekeeping that I don’t clean out the refrigerator until I need the yogurt containers for gardening.)
If you have to buy the buckets and the PVC, it’ll cost about $5.50 per container – two buckets and a short length of pipe.
Once your containers are assembled, all the remains is to put plants in them. We used our standard-issue hydroponic mix (two parts perlite, two parts peat moss, one part vermiculite), and we filled the reservoir with Peter’s Professional 5-11-26 fertilizer, a teaspoon dissolved in a little over two gallons of water.
You’re probably going to use potting soil, and ordinary water, because you think hydroponic gardening is the work of the devil. But you’re going to tell me why, aren’t you?