Intro: (Mostly) Self Watering Planter
Gardening can be both wonderfully rewarding or devastatingly discouraging. I've always been told I have a "green thumb" by friends who are chronically unsuccessful. This project was designed for just such a friend.
The main concept is a raised planter that drains into a reservoir. A pump in the reservoir has a timer so it waters the planter three times a day. The reservoir needed to hold enough water for three or four days. I wanted to conserve as much water as possible and reduce water loss from evaporation. The planter needed to be both cosmetically appealing and weather resistant. Finally, it needed to be cheap.
Step 1: Materials and Tools
2 "Totes": One large for the plants/dirt; One slightly smaller for the reservoir
Boards for framing
Plywood to support the planted tote
sink drain tube
T fitting that fits the soaker hose and vinyl tubing
assorted screws / nails / glue
Plywood to enclose the frame
Molding to hide my terrible carpentry (The stuff is magic, I tell ya.)
A few bricks to keep the frame dry and off the ground.
Saw (table, circular, chop, trim, jig, or even a hand saw with a miter box)
Another saw for cutting the plywood. top. I used both my jigsaw and reciprocating saw.
Assorted drill bits/spades
Appropriate tools for your fastening method (hammers for nails/brads, Screwdrvers/bits for screws, clamps for glue, etc.)
Appropriate tools for your finishing method (paint brushes/sponges, rags, etc.)
Step 2: The Frame
Walking my dog, I found an old pressure treated picnic table that had been disassembled and was destined for the land fill. The legs were pretty rotten, but there were quite a few great pressure treated 6 ft. 2x6s. I hopped in the truck when I got home ;) I ripped the 2x6s in half(not exactly, mind you, I'm still learning too) to give me several 2x3s. I used these to build my frame.
When framing your planter you want to consider a few things. You want it to be strong enough to handle the weight of the dirt in the upper container. Consider how the load is going to affect your method of joining the boards.You need the frame to be a little longer than the long side of the upper container so the tubing from the pump has room. For the short side the tote, you want it so the rim just barely fits inside the frame and isn't bearing the load. You need enough room in the bottom area for you to remove the reservoir container and service the pump. The top of the planter needs to be at a height that is both eye pleasing and comfortable to weed and plant.
I ended up framing with a hammer and nails. I pre-drilled holes slightly smaller than the nails to prevent splitting.Next time I'll glue and screw it. After I build the main frame, I put the frame topside down on a flat concrete slab. I then put the upper container inside the frame upside-down. Then I put the 3/4; plywood shelf on top of the tote.(I ended up messing this up somehow and had to cut about an inch from the top of the tote) Predrilled and nailed some supports on top of the plywood. Flip it back over and you end up with a flush well supported upper container.
Step 3: Optional Enclosing
I bought cheap plywood and cut it to size to enclose the frame and hide the plumbing, and containers. I ended up with some gaps so I bought some molding to hide the seams. I then cut a piece of plywood to fit the top, laid the tote upside down on the plywood and traced the tote. I a hole in the top slightly smaller than the tote with a jigsaw/ and reciprocating saw. Finish the whole project with your favorite method. I left it primer white so they could paint it whatever color they wanted.
Step 4: The Plumbing
Place the upper container into the planter on its shelf. Place the planter where you plan to use it. Pour enough water into the upper container that you can see which side the water flows to. Drill a hole thought both the container and the supporting shelf that the sink drain tube can snugly fit through. Super glue the sink tube in its place. Apply silicone adhesive to the seam around the drain tube to prevent seepage. Drill a hole the size of your vinyl tubing in the upper container that is just below where you plan your soil level to be and also in the support shelf between the container and the enclosure wall.
Cut your soaker hose so that when you make an oval from it it is about halfway between the wall and center of the container. Attach both ends of the soaker hose to the T fitting. Attach the vinyl tubing to the T and feed it from the inside of the container down through the and into the reservoir. Attach the tubing to your submersible pump. Drill a hole in the wall of your reservoir near the top and put a long piece of vinyl tubing in it. This allows water to drain from the reservoir if you overfill it or if you get a bunch of rain.
Step 5: Soil Considerations
Because this is set up to water 2 or 3 times a day, you want the soil to be well draining so your roots are sitting in water rotting. I mixed sand and potting soil for the bottom 1/3. I mixed peat moss, composted manure, sand, and potting soil for the upper 2/3. I put a piece of screen over the drain hole to help prevent the soil from falling down the drain.
Step 6: Plug It In
Plug the extension cord into the pump and then the extension cord into the timer. Fill up the reservoir a couple times a week and it will mostly take care of itself.