Dr. Joe Masabni
Department of Horticulture
Texas AgriLife Extension Service
Parsnip is a cold-hardy biennial of the parsley family, grown for the edible root. The cream-colored roots grow to 3 inches in diameter, are carrot-shaped and 6 to 15 inches long depending upon the variety.
Parsnips require the same basic cultural care as do carrots, including deep, sandy loam or loam soil that is fertile. Best quality occurs when harvested after a hard killing frost. In May or June plant seed in rows about 18 inches apart and thin seedlings to 4 to 6 inches apart in the row.
Select roots that are free of cracks and blemishes and 1 1/2 to 2 inches thick and 8 to 12 inches long. Roots that are too big and old are woody and should be avoided. Harvest 2 weeks ahead of the time you expect to eat them and refrigerate the roots. Roots stored in refrigeration will convert their starch to sugar and develop a sweeter flavor.