Problems with container gardening include not enough root space and the difficulty of effective watering. Top watering is slow and it is hard to get enough water into the container to satisfy the plant's needs. The double bucket approach to container gardening provides more soil for roots than many containers provide and there is enough water available so that even tomatoes usually don't dry out during the day. The PVC pipe delivers the water to the bottom of the container where the roots can more easily get at it.
Step 1: What You Will Need
Materials: 2- 5 gallon, nesting plastic buckets
2' x 1-1/2" PVC pipe (diameter is up to you but a larger diameter is easier to fill)
1- 3/4" x 6 screw ( I use hex head)
1- yogurt cup (8 oz.)
hole saw (for yogurt cup)
hole saw (for PVC pipe)
Step 2: PVC Fill Tube
Nest the buckets and stand the PVC pipe vertically next to them. At the rim of the upper bucket, mark the PVC pipe and cut to length.
Step 3: Drilling the Inner Bucket
Remove the inner bucket and turn it upside down. Using a drill-mounted hole saw or a reciprocating saw, cut a hole in the center of the bottom that is large enough for the yogurt cup but small enough so the cup is supported by its upper lip and will not fall through the hole.
Again using a drill-mounted hole saw or a reciprocating saw, cut a hole large enough for the PVC pipe. This hole is located near the side of the bucket.
Drill a few 1/4" holes in the bottom to let excess rainwater drain away from the roots.
Step 4: Drilling the Outer Bucket
Insert the inner bucket into the outer bucket and determine where the bottom is relative to the bottom of the outer bucket. This is about 2" up for my buckets. Remove the inner buckets and drill four or five 1/4" holes around the perimeter of the bucket about 2" from the bottom. These holes are to allow excess water to drain.
Step 5: Attaching the PVC Fill Pipe
Reassemble the two buckets. Insert the PVC pipe through the side hole in the bottom of the inner bucket. It should touch the bottom of the outer bucket and be even with the top of the inner bucket. Holding the pipe tight against the side of the bucket, drill a pilot hole through the inner bucket, near the top, into the PVC pipe. Install a screw to secure the PVC to the inner bucket. I use hex head screws because I find them easier to drive.
Step 6: Adding the Center Yogurt Cup.
With the inner and outer buckets assembled, insert the yogurt cup into the center hole and determine how much, if any, needs to be removed from the bottom of the cup. Using a knife, carefully cut the excess from the bottom of the cup. The bottom of the cup must be cut off in any case. It is only a matter of how much. Re-insert the cup to the hole.
The planter is finished. Fill it with potting soil, water the soil through the PVC pipe until excess water comes out the drain holes, and plant. Water daily until you get to know how much water is needed daily in your weather conditions and the planter's microclimate.
If you plant a tomato in your container, get one of determinate type and either stake it or use a cage for support. You may need to insert a rod deep into the soil to help keep everything upright in a wind. Go with bush-type cucumbers, squash or melons. Use succession planting for lettuce, beets, spinach, and radishes to get more from your container garden.