Grow bags are small canvas containers that are filled with soil and used to grow vegetables. According to the BBC, grow bags were once used under green house glass so that plant could be grown without planting directly into the greenhouse soil, allowing for greater crop variation. Grow bags can be used in areas where the soil is not suitable for tomato growing, or when there is not enough room for a tomato plant. Some bags can contain up to 3 tomato plants at once.
Fill the grow bag halfway with potting soil and compost and shake the bag, kneading it in places to loosen the soil, says the BBC. This prevents soil compaction. Use a loose, well-draining commercial potting soil, says Ohio State University.
Push the bag down onto the ground to lightly compact the soil and so that it sits without falling over.
Pierce the side of the bag and a few places on the bottom to aid in drainage of the soil, says the BBC.
Place stakes into the bag to hold up the tomato plant and fill the rest of the bag up says Ohio State University. Stakes will hold the plant up as it grows, and placing the stake and filling the soil around it will prevent it from falling over.
Dig small holes into the soil near the stakes and place your tomato plants into the holes, covering the root balls with soil, says the BBC. The root ball should be slightly below the lip of the grow bag. Water so the soil is moist.
Water regularly to keep the soil from drying out, applying enough water to reach the bottom of the bag. Do not allow the soil to dry out completely because this will cause drop of fruit and flowers, says the Iowa State University Extension service.
Fertilize using a water soluble fertilizer at 15-30-15 or 20-20-20 ratio every week, recommends the Iowa State University Extension.