This quick and easy crop is as healthy as it is tasty. Low in calories and a good source of iron, vitamins A and C and fiber, spinach also contains 3 grams of protein per serving. Sow in early spring 1/2" deep in rows 6-8" apart in the bed. Later crops can be sown in the shade of tall growing plants to extend the season, as spinach is surprisingly heat tolerant. 35-40 days to maturity.