This unique feature trains the roots to grow downwards instead of growing circular and becoming root bound Plug plants are sustainable in their trays. Plug Plants do not have to be planted immediately when you receive them. You can just set them in the sun and water once per day, and they can be transplanted weeks later. Works great for propagating tomatoes, peppers, eggplant, okra, watermelon, lettuce, chard, broccoli, cauliflower, collards, kale as well as lots more. Plug Plants are more reliable. To ensure a good root system and better plant health plugs that are raised professionally under controlled conditions in a greenhouse during their formative period. In order to help the plant reach its maximum potential during the harvest/blooming period. Plug plants will produce more vegetables/flowers. Since these plants are healthy with a good root system, Plug tray plants grow quickly and will be better able to withstand pests and disease. Some varieties of plants can only be grown from cuttings. Some hybrids specially bred for unusual coloring, and varieties of plants such as Lantana, Dahlia and Calibrachoa can only be grown reliably from cuttings. With plug plants, you are not limited to seed varieties of plants. You can order Plug Plants that have been propagated from cuttings to add to your seed-grown plants.