Parsnips are a root vegetable that is similar to carrots. Look for small to medium parsnips that are firm and have smooth skin. Don't buy parsnips that are shriveled, limp, cracked or spotted. Store parsnips in a plastic bag for up to 2 weeks. Peel and trim ends just before using. One pound is equivalent to about 4 medium parsnips or 2 cups peeled and chopped.