Introduction: The Dearthbox: a Low-cost, Self-watering Planter
Joining many other excellent earthbox instructables, meet ours, the Dearthbox! The Dearthbox costs about $13-16 per box, and can grow up to three plants, depending on the type of plant. At our house in CA, we've been testing these out for the last month or so. Our tomatoes are thriving and it's a relief to know our plants aren't parched in the afternoon heat.
Even if you've already planted stuff, you could still transplant to the Dearthbox and save some water this summer.
This instructable shows you the materials we used, the steps we followed, and how to plant a fairly big plant, as well as how to plant seedlings.
Step 1: Gather Your Materials
If you already own most of the cutting tools and the drill, this instructable costs about $13-15. We got everything at Home Depot, but you can find similar stuff at any hardware store.
2 big paint buckets that stack (~5 gallons each)
1 plastic tub OR drain grate (The height of the tub/drain grate should be approximately the same height as the gap between the two buckets when stacked)
1 2' long 1" diameter plastic pipe (make sure it is longer than the height of the buckets when stacked)*
1 mesh baggie (find them as packaging for fruit, veggies, other stuff!)
drill with 1 inch bit and 1/4" masonry bit
utility knife with extra blades
tarp (collects all the plastic bits!)
black plastic garbage bags
seedlings or established plants
*I've read different things about using PVC after making this first version, which does use PVC. This project is made entirely of plastic, so if plastics in general bother you, you probably should not make this. If PVC specifically bothers you, it's easy to find other plastic pipes that will work, just poke around the garden supply store. Also, Greenpeace has a big database of alternatives. What do you think about PVC? What alternatives have you discovered?
Step 2: Mark the Buckets
1) Hole for wicking basket
On the bottom of the first bucket, trace your drain grate or plastic tub and mark a circle on the bottom of the first bucket. Be sure your circle is smaller than the lip of the container.
2) Hole for pipe
Next, mark a hole for the pipe, also 1/2" from the wall of the bucket
3) Side drainage holes
On the side of the second bucket (not the one you've already marked!), measure and mark drainage holes. Finding this measurement is pretty easy--just place the buckets one next to the other and figure out how much of a gap there is between them when they stack together. Mark just below that line. Mark two drainage holes, one on each side.
4) Second hole for pipe
On the lid, mark a hole for the pipe (1/2" from the edge)
5) Holes for plants
Next mark holes for the seedlings on the lid, or one big hole for an established plant
Pictured is the finished bucket lid, so you get a sense of what the holes will be doing once you plant your dearthbox.
Step 3: Cut the Holes in the Buckets
Cutting plastic kicks up a lot of little plastic dusty bits. Protect your eyes and nose and mouth accordingly.
For the big holes on the first bucket and the lid, start them with a drill, using a 1" masonry bit. Use the utility knife to widen the holes.
Cut drainage holes in the bottom of your first bucket, using a 1/4" diameter drill bit.
Next, cut the side drainage holes on the second bucket.
Remember, do not cut the side drainage holes in the bucket with the holes in the bottom.
You can smooth the edges with the file if you want.
Note that I don't have a picture of this process for the bucket lid, but you want to do the same thing for the pipe hole and the plant holes you marked in step 2 on the lid.
Step 4: Prepare the Pipe
Cut an angled segment from the bottom of the pipe, using your hacksaw.
The reason you're doing this is so that water can flow out of the pipe when it's at the bottom of the buckets.
Step 5: Assemble the Wicking Basket
Either line the drain grate with mesh, or cut holes in your solid plastic container. We found these as a three pack at the dollar store. You could also use food containers, etc., as long as there is enough of a lip and they are the right height.
Even though it's significantly more expensive, I highly recommend the drain grate option. They both seem to be performing equally well, but the drain cover just seems sturdier and better.
The last photo is of the wicking basket with dirt inside already. You don't have to do that part yet, but this shows you how the netting helps contain the dirt.
Step 6: Assemble the Bucket!
Place the assembled wicking basket in the bottom of the bucket.
Push the pipe through the holes in the lid and the bottom of the inner bucket
Stack two buckets, with the basket hanging between the two.
Now you're ready to plant!
Step 7: Planting
Use your favorite potting mix, compost, plants, seedlings, etc., and put it all together! This part is really up to you, but I would encourage you to soak the wicking basket first, and only use a small amount of fertilizer. The bucket recycles it, so you probably won't need to add fertilizer again for a very long time.
If you cut smaller holes in the lid, gently thread the plants through the holes before lowering the lid completely.
If you cut one big hole, line the top of the bucket with black plastic. This helps keep the potting mix moist. (see Mr. Beefhead's comment about why it's important to use potting mix)
To water the dearthbox, just pour water down the pipe. You know it's full when water comes out the drainage holes on the sides. We started with moist earth to make the wicking basket's job easier.
Thanks for checking out our instructable! If something doesn't make sense, please tell me and I'll fix it!
ps: we just got our copy of Kelly Coyne and Erik Knutzen's The Urban Homestead (http://homegrownrevolution.com) in the mail, and it's great! Their SWC recipe is really really similar to ours, but with a few cool extras and best of all, lots of advice about which plants do well in SWCs and which plants do not. You should definitely check out their book if you're using or thinking about using any sort of earthbox.