Growing greens is a great way to keep vegetable gardens productive throughout the winter because they tolerate cooler weather and are easy to grow. Mustard greens have broad, wavy leaves with a dark green (or purple) color. They grow upright, supported by coarse longitudinal veins. The Florida Broadleaf variety has large leaves with a sawtooth edge; the Green Wave features bright lime green, ruffled leaves; the Southern Giant Curled features oval, bright green leaves with a fringed edge; the Tendergreen (mustard spinach) features dark green, glossy leaves with light-green midribs; and the Garnet Giant has broad purple leaves with slightly serrated edges.
According to the LSU AgCenter, greens can be planted from mid-July through early November, and again from late January through early May. Plant greens in an area of the garden where you previously had plants in the nightshade, legume or cucurbita families for disease management purposes. Harvesting can begin five or six weeks after planting.
Space mustard seeds about three inches apart, and plant four to six weeks before the last frost in spring and the first frost in fall. Even better, do several plantings a couple of weeks apart to ensure a continuous supply of these leafy greens. The soil should be between pH 6 and 7; side dress the plants with fertilizer three to four weeks after planting. Harvest by collecting only the large leaves or by cutting the plants to within an inch of the crown to allow for regrowth.
Mustard greens do not tolerate heat well and will therefore bolt (mature and produce a flower stalk) in the spring. Cool weather, adequate water and regular fertilization with nitrogen will allow your mustard greens to produce more leaves instead of flowers.
Other vegetables to plant alongside your mustard greens include rutabagas, radishes, carrots, beets, shallots, onions and garlic, plus herbs like parsley, dill, celery, cilantro, fennel, oregano, thyme, sage, chives, mint and rosemary.