While flipping through the TV channels, you've probably seen a variety of grow bags you can hang to make use of vertical gardening space. These bags are not made of anything special -- you can make your own growing bags from a simple, reusable grocery sack at a fraction of the price of store-bought grow bags. While the bags themselves aren't particularly attractive, you can add several plants to each bag which help cover the bag as they grow.
Cut several X-shaped holes in all sides of a woven plastic, reusable grocery bag, spacing the holes about 6 inches apart. The slits should be the same size as the transplant root balls. Use a razor knife to cut the slits without tearing the bag. If one side of the bag will be hung against a wall, do not add holes to that side.
Fill the bag with a lightweight potting mix to just below the bottom series of holes. Mature plants and well-watered soil can be quite heavy, so use a soilless mixture, such as 1 part sphagnum peat moss to 1 part perlite to reduce the weight of the bag.
Push a small seedling root ball through each of the X-shaped slits at the bottom of the bag. The plant should run perpendicular with the sides of the bag. Cut away part of the slits, if needed, so the slits don't rub against the root ball.
Push straw or newspaper strips into the slits to prevent the root ball and soil from falling out through the holes.
Add more potting mix to fill in around the root balls. Fill the bag to just below the next series of holes. Add more plants through the second series of holes, then fill in with more soil. Repeat until you plant each hole in the grow bag.
Slip the bag handles over a hook to hang the bag. Alternatively, you can slide the handles onto a board or pole and hang it to span an overhead pergola or ceiling rafters.
Water the potting mix from the top of the bag until excess water drains through the bottom of the bag. Drainage holes are not necessary because water drains easily through the woven plastic strips.