So I told you all I was going to be building some self watering containers for the garden. I figured I’d document the process and share it with you. Feel free to modify as desired!
Stuff You’ll Need
- Two 4 Gallon Square Buckets – One for a water reservoir, and one for soil
- Some sort of container to hold your ‘soil wick’
- Some landscape cloth
- An 18″ length of 1″ NSF Certified Schedule 40 PVC (If you’re worried about PVC, feel free to replace with something similar)
Step One – Drill Drainage Holes In The Soil Bucket
So unless we want to swamp our plants when it rains, we have to have good drainage. So take a drill with a 1/4″ bit or so, and drill a bunch of drainage holes in the bottom of the soil bucket.
Note two important things in the picture below … we don’t put holes in the middle, and we don’t put holes in one corner of the bucket. This is pretty important for reasons which will become apparent later on.
Don’t by shy with the holes, and don’t be too picky about where they go. Just have fun drilling holes all over the place.
When you’re done, it should look kinda like this:
Step Two – Drill Drainage Holes In The Reservoir Bucket
All the drainage holes in the world won’t help if our reservoir can fill up. So we need some drainage holes in the reservoir bucket to prevent that.
Stack your two buckets the way they will normally be (soil bucket stacks inside the reservoir bucket) and drill two 1/4″ holes into each side of the reservoir bucket right below the bottom edge of the soil bucket. In the pictures you can pretty clearly see the line where the soil bucket stops.
Honestly, I don’t know if that’s enough drainage, but I figure it’s good enough for now.
Step Three – Prep Your Soil Wick
The soil wick makes the whole system work. It’s basically a container of soil that actually sits in the water. Similar to a candle wick, it helps the moisture move up into the main planting area.
You can use just about anything here, including special baskets, but I just some old plastic seedling containers I had lying around. Yeah, I’m cheap. Oh well.
Incidentally, you need something that is at least 3″ tall to function here. That’s because the distance between the top edge of the bottom of the soil bucket and the bottom of the reservoir bucket (did that make sense?) is exactly 3″ using 4 gallon square buckets. Using something else? Measure it!
Unfortunately the containers I had were just short of that. So I just stacked them. Before stacking them I cut a square of landscaping cloth to go between them. This keeps the soil from leaking through the drainage holes in the wick container.
Step Four – Cut A Hole For your Wick Container In The Soil Bucket
You now need to draw an outline of your wick container onto the bottom of your soil bucket. Like this:
Once that’s drawn out, now cut it out. You have two options. Use a Dremel type tool, or drill holes in the corner and use a jig saw or hacksaw to cut it out. If you have a circular soil wick container, have fun!
I used a Dremel because it’s way easier, but use whatever you have. You’ll end up with something like this:
Step Five – Cut A Hole For Your Fill Tube In The Soil Bucket
Now you need a hole for the PVC pipe you’ll use to fill the reservoir. If you’re using a 1″ PVC pipe like I do, you’ll need a 1-3/8″ hole. Use either a hole cutter or a spade bit. I couldn’t find a hole cutting bit at our local box store for under $30 (who knew this was such a rare size?), so I used a spade bit.
If you use a spade bit, be SUPER careful and go slow … they bite into the plastic really easily. Try to find a hole cutting bit, they’re MUCH EASIER and much safer. For my next batch, I’m going to go find a hole cutting bit somewhere. I did not like using the spade bit. At all.
Seriously. Be careful with a spade bit. Mine even managed to draw blood a few times.
Anyhow, this hole gets drilled into the spot where you DIDN’T put drainage holes. See how that worked out? Awesome!
Step Six – Prep Your Fill Tube
You have a couple options here … you can cut it off at an angle, or you can drill a bunch of holes in the end. The point is to make it easy for the water to exit the pipe and go into the reservoir.
I have a drill press, so I just busted out a fairly large bit (don’t recall what size offhand) and drilled a bunch of holes in the last 2.5″ of the pipe. Just like the drainage holes, I was pretty random and just drilled holes until it seemed like it was good.
Step Seven – Cut Your Soil Bucket Landscape Cloth
We need a permeable soil barrier between the actual soil and the drainage holes we drilled in the bottom of the soil bucket. A muddy reservoir is not part of the plan. Luckily, landscape cloth provides us with a great solution here!
Cut a square of landscape cloth that’s a bit bigger than the bottom of your bucket. Don’t worry about being precise here either. Just get reasonably close.
Now take a knife, utility knife, whatever, and cut a big X in the center where the soil wick goes. To make this easy, just put it on the bucket and cut from corner to corner of the actual soil wick hole. Cut a similar X where the fill tube hole is as well while you’re at it.
Please note that those sexy hands are NOT mine, but belong to my wife. And the rest of her is even better! But I digress…
Step Eight – Insert The Fill Tube Into The Landscape Cloth
Pretty straight forward. The picture pretty much tells it all.
Step Nine – Put The Cloth Into The Soil Bucket
First, stack the soil bucket into the reservoir bucket.
Next, carefully take the fill tube and insert it into the hole in the soil bucket and drop it down until it’s resting on the bottom of the reservoir bucket. While you do this, try to keep the landscape cloth reasonably aligned with the X for the soil wick close to the middle of the soil bucket.
Finally, insert the soil wick container into the hole you cut for it. In a shocking development, the flaps from the X you cut in the landscape cloth go down nicely and seal up any imperfections in the hole you cut way back in step four.
All in all, you should end up with something like this. Feel free to rearrange the sides of your landscape cloth like I did if you want.
Step Ten – Fill ‘er Up!
Now, fill with your favorite soil. I suggest using a trowel first to fill the soil wick and put a thin layer over the bottom of the soil bucket. This lets you control where the soil goes a bit better so you can make sure the landscape cloth stays nicely arranged. Once that’s good, feel free to use a shovel.
Yes, that’s a 55 gallon steel drum … we use them for mixing soil because we can put all the ingredients in, seal it up, and just roll it around until it mixes. Sounds awfully hokey, but it’s amazingly entertaining. I’ve considered rolling it down the big hill outside our house but I don’t think the neighbors would like it that much…
Plant away! Hope this works out for you, it worked pretty well for us. Holler if you have any questions