Gardening in restricted spaces Just about any herb or vegetable can be grown in a container. Look for seed packages labeled dwarf, bush, or small if space is limited. The University of Maryland Cooperative Extension recommends media depth of four to six inches for things like leaf greens, Asian greens, mustards, garlic, radish, basil, cilantro, thyme, mint, and marjoram. Salad greens and some herbs have shallow, fibrous root systems and are well suited to shallow containers with a large surface area. Eight to twelve inch pots are ideal for beans, beets, chard, carrots, cabbage, pepper, eggplant, tomato, squash, rosemary, parsley, lavender, and fennel. Pot
Leaf valve Leaf valve A leaf valve is a one-way valve (check valve) consisting of a diagonal obstruction with an opening covered by a hinged flap. Patents exist in the United States which specify the mechanical use of leaf valves to control various types of fluids. United States Patent 4930535 is a folding leaf valve which is described as a valve that, "folds upon itself to provide positive sealing of a pressurized chamber under a variety of pressure conditions. In particular, the valve stem folds to effectively close the lumen and provide a positive seal even at low differential pressure." United States