Beta vulgaris var cicla
Swiss Chard thrives in cool weather, so plant as soon as the soil can be worked, or at soil temperatures of 10-29°C (50-85°F). For a fall crop, plant again in late August or early September. Sow thinly, about ½" deep. Thin plants to 1-3 inches apart, in rows 12-24 inches apart.
Full sun but will tolerate light shade, with a soil pH of 6.2-7.0. Moderate feeder, requires a fertile, well cultivated soil. Enrich soil with plenty of compost and well rotted manure. Needs even moisture for good growth. Drought and warm temperatures will cause premature bolting. For all season production, provide regular feedings with a well balanced fertilizer or compost tea.
The tender, flavourful vitamin-rich leaves may be cut as soon as they are big enough to eat. Harvested regularly, Swiss Chard will continue to produce fresh greens.