SEASON: Although available in markets year-round, they are at their prime in spring and fall.
CHOOSING: Look for greens that are not wilted, have no physical damage, and have no areas that are turning yellow or brown.
STORING: Place greens in a produce storage bag in the coldest part of the refrigerator. Most will stay fresh for about a week.
GROWING: Most gardeners will have success growing mustard greens, collards, and Swiss chard in the spring and again in the fall. In warm, temperate gardens, greens will live through the winter. If your area has cool summers, you can grow them then, too.
Greens need full sun and rich soil to produce a lot of leafy growth very quickly. Space mustard greens 4 to 8 inches apart, collards 12 to 18 inches apart, and Swiss chard 8 to 12 inches apart. Apply a liquid fertilizer at planting time and again every three to four weeks.
In a well-prepared bed, sow seeds or set transplants two to four weeks before the last spring frost. Plants will mature in spring, making quite a display of light yellow flowers when the weather gets hot. Pull them out to make way for summer veggies.
For a fall and winter harvest, sow seeds or set out transplants in late summer or early fall. The plants will mature as the days get cooler. This is ideal for greens because light frosts actually sweeten them. Collards are the most cold-hardy of the bunch, and they frequently provide fresh greens all winter long. Harvest the outer leaves from the bottom, moving up, as soon as the leaves are large and the plant is established.