Fill a 12-inch hanging plant pot 1/2 full with potting media. Equal parts of potting soil, peat moss and perlite make a good lightweight soil for containers. Potting soil or garden loam are too heavy for containers and compact easily with watering.
Add 1-1/2 tbsp. of 10-10-10 fertilizer to each 3 gallons of soil. A 12-inch pot holds approximately 3-1/2 gallons of soil.
Position three to four seedlings evenly spaced in a 12-inch pot. Fill in around the roots with soil and firm down lightly to secure the seedlings.
Water the seedlings thoroughly until water runs freely through the bottom of the pot.
Hang the tumbling Tom tomatoes in a sunny location receiving at least six to eight hours of direct sunlight a day. Sun exposure does not need to be consecutive. Three to four hours in the morning, some noontime shade and three to four hours of direct sunlight in the afternoon works well.
Water the tomatoes whenever the soil dries. Hanging plants dry quickly in the summer sun. Tumbling Tom tomatoes may require daily watering. Water them until the water runs freely through the bottom of the pot.
Apply water-soluble fertilizer on a seven- to 14-day cycle following the recommended application rate.