Plant in spring up to a month before last frost in fertile well drained soil at the edge of the garden where it may grow undisturbed. space crowns 12-18 inches apart in rows 5-6 feet apart. Plant crowns in a trench around 6 inches deep. Be sure the crowns are right side up and spread out the roots. cover with 3 inches of soil. These steps may seem high maintenance, but the rewards are your own asparagus year in and out.