Provided that they have sufficient nutrients and adequate soil, vegetables will grow in any container in which you place them. Tomato plants can grow in a wide range of containers, from soil bags that are nothing more than the manufacturer's packaging with a few holes cut in them, to the popular brand Topsy Turvy tomato plants, which grow in a soil bag that hangs from a hook or stand.
Select tomato plants to grow. Tomato plants that will grow in bags range in size from tiny, compact plants such as cherry tomatoes or dwarf varieties like elfin or Tiny Tom up to full-sized tomatoes such as Best Boy or Beefsteak.
Read the tag that is attached to the tomato's container by the nursery grower. This gives you an indication of how much soil each tomato needs to grow. Dwarf varieties such as Tiny Tom grow in only 1 gallon of soil, while large varieties such as Beefsteak require at least 5 gallons of soil to thrive.
Choose a package of potting soil in the quantity suggested by the tag of the tomato plant.
Puncture several holes in the underside of the bag to facilitate drainage. Use a thin implement, such as a needle or the tip of a knife, to keep the drainage holes so small that they will drain water without allowing soil to escape the bag.
Cut an X-shaped slit in the top of the bag. Create a planting pocket by shoving the soil in the bag aside.
Slip the tomato's root ball free of the plant's container by turning the plant on its side. Support the tomato by its stem and tap the bottom of the container with your hand to loosen the roots from the plant. Slip the tomato free and place the root ball into the planting pocket. Close up the soil around the tomato's root ball.
Cover the grow bag with mulch to disguise the bag's appearance and to help hold moisture in the grow bag.