There are many different cell types and sub-types involved in the immune system. Some of the main types include: Lymphocytes: are white cells which circulate between blood and lymph. They play an important role in fighting infection.
After about 50 to 60 days, beets are ready to harvest. Not only can the roots be dug up and chopped to add flavor to a meal, but the greens of the beets can be harvested periodically and put in salads. Given how well these beets fare in different weather conditions, they can be grown several times in a summer.
How to Sow. 1  Sow beet seeds in well-worked, well-drained soil in full sun after danger of frost in spring. 2  Beets are sensitive to acidic soils and prefer a pH of 6.0 â 7.0. 3  Sow thinly in rows 12 inches apart and cover with Â½ inches of fine soil. 4  Seedlings emerge in 14-21 days. 5  Thin to stand about 3 apart when seedlings are 1-2 tall.