Growing tomatoes upside down in a homemade planter is a way to keep tomato plants off the ground where they are exposed to pests and diseases. Also, you avoid using a trellis to support tomato plants. The upside down planter saves space if you are gardening on a porch or balcony and is easily accessible if you have limited mobility.
Find a location to hang your planter that receives at least 6 hours of sun per day and is conveniently located near a source of water. Avoid shaded areas as tomato plants cannot produce tomatoes without enough sunlight. The upside down tomato planter needs regular watering, so locating the planter near a source of water important. Remember that water and soil particles will drain from the planter when water is added, so avoid locating planter over patio furniture or other items you don't want to get wet.
Find a black bucket; tomato plant roots need darkness to thrive. If you use a white bucket, paint the outside of the bucket with black outdoor paint that is suitable for painting plastic.
Drill a 2 to 3 inch in diameter hole in the bottom of the bucket for the tomato plant.
Carefully push the small tomato plant into the bottom of the bucket so the tomato plant will be facing out and the root system will be located inside the bucket. Add enough sphagnum moss around the roots of the tomato plant so it is secured in the bucket and cannot fall out through the hole in the bottom once the planter is hung up by the handle.
Hang bucket from the handle in the area where it will be located and gently fill with a mixture of one-half compost, one-fourth perlite and one-fourth sphagnum peat moss to 3 inches from the top of the bucket. Add a 1-inch layer of mulch to conserve moisture. Water well to settle mixture and fertilize regularly with a fertilizer listed for tomato plants on the container label.