1. Lay the bag flat and poke drainage holes all over one side. Flip it over, smooth the bag into an even layer, and use a sharp knife or scissors to cut out a rectangle about two thirds the size of the top of the bag.
2. Plant lettuce, spinach, radish, or other seeds in the exposed soil mix, following their packets’ instructions. Water and feed as for potatoes.
3. Harvest just the outside leaves of the plants to extend your yield; as the plants keep growing, you can keep harvesting. Or tuck in a seed or two when you do remove a whole plant so you’ll reap another round of greens. You can start growing greens (and radishes, too) in very early spring, as soon as the nights don’t drop much below freezing. Greens appreciate some shade in the heat of summer, so during the hottest months you may want to move your salad bag to a spot that becomes shady in the afternoon.
Whatever you choose to grow, at the end of the season, dump the bag of used soil into a raised bed or more permanent container or spread it in a corner of your yard that needs it.