Spinach (Spinacia oleracea), chard (Beta vulgaris var. cicla) and mustard greens (Brassica juncea) are just a few of a group of vegetables loosely referred to as greens because they are grown for their tender, vitamin-rich leaves and stems, which happen to be green in color.
Spinach naturally grows well only in cool regions. In warmer areas, gardeners often substitute Malabar spinach (Basella alba) or New Zealand spinach (Tetragonia tetragonioides), both of which are unrelated to true spinach but taste somewhat like it, and are therefore used like it. Chard (or Swiss chard) is a relative of the beet, but is grown for its tops only. It is easy to grow and prolific in an organic garden. Mustard greens have a piquant flavor and mature quickly.
When growing greens in your garden, you can control how they are grown and planted, and can make sure they are completely organic, so you don’t have to eat any pesticides or chemicals often used by commercial gardeners.
Spinach, Swiss chard and mustard greens have the same soil and nutrient needs: a nonacid soil (with a pH of 6 to 7.5) enriched with organic matter and high in nitrogen. With the exception of Swiss chard and Malabar and New Zealand spinach, greens are cool-weather crops; in hot weather they will “bolt” (produce seeds and stop growing). Greens are resistant to cold and, if they are given a thick mulch cover, will naturally thrive through a few light frosts.