Intro: Earth Box From a Plastic Barrel
What can you do with empty 55 gallon plastic barrels? Why not recycle them into an attractive low maintenance container garden. Earth boxes are self watering containers which take the work out of gardening while providing healthier plants and more vegetables. While there are other earth box designs, my goal was to remake plastic barrels into attractive pots which could be placed anywhere around your house. Here's how you do it.
Step 1: Materials
A 55 gallon plastic barrel and a plastic tube are the main components of the earth barrel. I used an empty barrel we get soap in at work and the tube is a recycled plastic leg from a storage shelf. Both were free and looking for a new job. My cost per earth barrel was about $4 because I painted them and already had the tools. One can of spray paint will put 2 coats on 2 planters.
List of things you'll need:
55 gal barrel
1 1/2" PVC pipe 20" long
4 zip ties
10 long aluminum rivets
3/4" PVC plug
Spray paint for plastic (optional)
Plastic epoxy to fill punctures if necessary
Old towels -- it's impossible to get these barrels completely empty so you will make a small mess when cutting your barrel
Tools: drill and bits, jigsaw, hole saw, riveter, crescent wrench, Sharpy, pliers
Step 2: Preparing Barrel
The first step is to rinse out the barrel and plug the access holes (if necessary). A spigot was used to dispense soap from my barrel so I inserted a 3/4" PVC plug into the hole. Check the top of your barrel (end with holes) for places where air holes may have been made by simply puncturing the barrel. Air holes are made to allow the barrel to breath and can be patched with a bit of plastic epoxy. Air holes in the bottom are not a problem.
Do this step first so as not to forget it later. Once filled with soil, this pot weighs around 120lbs and is hard to lift. You will not be happy when you see water running out from under your "earth barrel".
Step 3: Cutting the Barrel
First mark a line around the barrel 4" from the bottom and a second 18" from the top (photo 1). To more easily mark the barrel I made a Sharpy holder/stand out of scrap wood (photo 2). Three 15/32" diameter holes are made at 4", 8" and 18" from the floor in the stand. The 8" height will be used later. While it's not critical to make perfect cuts, this stand helps you start with a straight line at least.
Next cut the barrel into three pieces using a jigsaw (photo 3). Drill holes in the middle section next to the lines for introducing the jigsaw blade and proceed to cut along the mark until you've made both cuts.
Step 4: Cutting the Lower Cylinder
Setting aside the top and bottom pieces, mark a rectangle 8" wide by 28" long on the middle piece (photos 1 & 2). Cut this piece out without cutting completely across the middle piece as we will be cutting another 1 1/2" band from the other side later. Drill a series of 3/8" holes in the 8" x 28" piece (photo 3). These holes are to allow water to perculate into the soil. There is not a set number of holes necessary so you can drill more or fewer holes as you like.
Step 5: Riveting the Cylinder
Work the perforated plastic piece into a cylinder and clamp in place (photo 1). Drill 1/8" holes and insert long aluminum rivets to hold the pieces together (photos 2 & 3).
Step 6: Make the Seperator Screen
Turn the barrel bottom upside down and mark a circle 1/2" small than the internal diameter of the bottom cylinder (photo 1). A one gallon paint can makes the perfect sized circle for this project. Cut out the circle with a jigsaw (photo 2).
Place the bottom cylinder over the hole and mark around the outside (photo 3). This is so you do not drill holes in the bottom too close to the cylinder. While the cylinder is in place, also mark 4 holes to be drilled in the cylinder and 4 holes in the bottom where zip ties can be used to secure them together. Drill 1/4" holes at your marks in the bottom and cylinder.
Drill 3/8" holes in the bottom which should actually now be called the seperator screen (photo 4). Again there is no preset number of holes so drill as many as you'd like. When you are finished drilling, attach the cylinder and seperator screen with 4 zip ties. The zip ties insure the cylinder stays centered over the hole.
Step 7: Adding the Water Spout
A water spout allows you to fill the bottom water reservior. You'll need to drill a hole in the seperator screen for PVC pipe to pass through (photo 1). For this you'll need a hole saw larger than the outside diameter of the pipe. The fit does not need to be tight so anything close is fine.
Cut a 45 degree angle on the end of your PVC pipe to allow water to easily flow into the bottom reservior (photo 2). Photo 3 shows how the assembled internal components sit inside the barrel.
Step 8: Making a Drain Hole
One last step, you need to make a drain hole to prevent overwatering. Make a mark 8" from the floor and drill a 1/2" hole below your mark. In this way, water cannot get above the seperator screen. Some people like to have 3 or 4 holes in case your earth box isn't setting level.
When you get ready to set up your earth box, put the water spout and the drain hole on the same side so you can see when it's full.
Step 9: All Done!
If you're not planning on painting your earth barrel, you're done. Simply put the seperator screen inside the top of the barrel with the cylinder on the bottom. Insert the PVC pipe and you're ready to fill with dirt.
If you want to paint, you can buy spray paint made for painting plastics at any home store. One can will paint 2 planters. I thought it was worth the extra effort since I'm putting these on our patio.
Step 10: Filling the Earth Box
Make sure you have your planter in the right place since it will be hard to move. It holds 3 cubic feet of soil, and around 8+ gallons of water (estimate), which is about 200 lbs when full. So chose wisely.
The bottom cylinder should be packed tightly with wet soil (not mud). I pack an inch or so and spray it with the hose. Once the bottom cylinder is full, you'll want to mist the dirt as you pack it but not as wet as in the cylinder. Fill your pot to the brim with a little crown in the middle (photo 1).
I made a circle of fertilizer in the middle after digging a little trough (photo 2). I put 2 cups of 10-10-10 general use fertilizer in the trough. The fertilizer sits under the plastic which keeps it from dissolving too quickly and will feed your plants all season. When next year comes, remove the old plastic, dig out and replace the old fertilizer and you are ready to go.
The black plastic serves several purposes including water conservation, weed control, and it protects the fertilizer bed (photo 3). Since I live in the South, I'm also covering the black plastic with pine straw because I'm afraid it might absorb too much heat. I could have used white plastic, but I already had the black plastic and I think the pine straw looks nice. Our pine trees donated the straw;-)
The blue strap holding the tarp on was the last cut from the old barrel. You could use rope or a bungy cord, but this was easy and I had the scraps to use. The next step shows you how.
Step 11: Plastic Band Strap
On the remnant of the middle section, mark a line 1 1/2" from the edge and cut with your jigsaw (photo 1). You'll also need to cut a 1 1/2" x 7" piece from the scraps. Cut the big band and use the 7" piece to rejoin the ends with a 2" gap (photo 2). Two long aluminum rivets on each end do the trick. This makes the strap the right size to go around the barrel and plastic.
I hope you have found this instructable valuable and easy to follow (photo 3). "Earth Barrels" are a great use for unwanted barrels headed to the landfill. Fortunately, one barrel provides almost everything you need to grow some fresh veggies or flowers with minimal maintenance.
Comments are appreciated and I am anxious to hear suggestions for improvement.
Step 12: Addendum: Adding a "trellis"
I wanted to plant some pole beans and needed something for them to climb on. So before filling the pot with dirt, I drilled five 1/2" holes in the seperation screen to allow placement of plastic poles. After filling with dirt and installing the plastic, I simply wired the tops of the poles together to secure them. Flexing the poles inward creates tension against the inside of the pot bottom by the poles and makes a very stable trellis. Much better than trying to add poles to the outside of the pot later. Just waitin' on the beans.