Upside-down tomato planters have some advantages over traditional tomato growing. The tomatoes hang down and don't require support, and the plants get good air circulation, promoting a healthier plant. Choose a small tomato variety for upside-down planting. Larger varieties need more soil and root space and don't grow as well in a container. With smaller varieties, two plants can be planted in a 5-gallon container.
Purchase the 5-gallon bucket or other container with a sturdy handle. Cut a 2- to 3-inch hole in the bottom of the bucket. A hole saw will do the job easily on a plastic bucket.
Prepare a place to hang the bucket. The filled bucket is quite heavy, so make sure you have a sturdy place to hang it.
Pre-moisten enough potting mix to fill the bucket. Mix in a slow-release fertilizer for tomatoes.
Hang the bucket on the support. Place the tomato plant through the hole so that the plant hangs out of the bottom with the root ball inside the bucket. Add about 4 inches of potting soil to the bucket.
Adjust the depth of the tomato plant in the bucket so that it is buried in potting mix up to, but not covering, the first set of leaves. Firm the soil down and around the root ball.
Fill the bucket with the moistened potting mix. Pack the bucket full.
Water the tomato plant generously from the top of the bucket. The tomato plant should be hanging out of the bottom of the bucket.
Give the plant plenty of water each day. Fertilize with a water-soluble fertilizer, following the directions on the package.