(Spinacia oleracea) True spinach is very cold tolerant, one of the first crops planted at winter’s end, as well as one of the last in early fall. In zone 6 and above, it’s possible to harvest at least a few leaves occasionally all winter long, and farther north, it may be possible with row cover or high tunnels. We list some warm weather spinach substitute here as well, and these are quite the opposite: they yield abundant greens in summer’s heat, when growing true spinach would be out of the question. Spinach, whether true or warm season substitutes, requires lots of nitrogen and water.
50 days. The old standard since 1925, does better in hot weather than most....
50 days. Big leaves to 10 inches long, smooth and deep green in color....