Rainbow Mix' chard is a fun seed mix with stems of pink, orange, red, and yellow! Swiss chard is one of the most popular and easiest greens you can grow in your garden. Direct sow outdoors 2-4 weeks before the last frost. Plants take 50-60 days to mature but you can always pick outside leaves when young. Continue to sow Swiss chard seeds right up to early August for a fall crop. Always grow your Swiss chard plants under floating row covers to prevent leaf miners from attacking the leaves.