When you are growing tomatoes in an upside down hanging planter, you have some benefits that others don't have. The bucket or bag planters allow more air circulation than the plant would receive in the ground, and you can easily move the plant if needed. Making an upside down tomato plant holder is easy enough to do in as little as 1/2 an hour with things that you might even have around the house already.
Drill a 2-inch hole in the bottom and the cover of the bucket with the 2-inch hole saw bit.
Place two coffee filters together and cut a 1-inch slit in the center. Place the coffee filters in the bottom of the bucket.
Lay the two boards across the arms of a patio chair. Place the bucket on top of the boards so that the hole is not blocked. Insert the tomato plant through the slit in the coffee filter. Do this from the inside out, gently so as not to damage the stems and leaves. The coffee filters will prevent the soil from falling out of the bucket.
Add soil to the bucket while holding onto the root ball. Gently pack the soil around the roots and continue filling the bucket with soil until it is full.
Place the other two coffee filters on top of the soil where the cover hole will be. Add the cover and make sure that it is sealed tight. Watering will be done through the cover hole and the coffee filters will protect the soil from eroding when water is added.