A perennial vegetable, asparagus produces tender spears in the springtime year after year. Asparagus performs best when planted in full sun and in well-drained, sandy soil. Clay soil can be improved by mixing in compost into it. Because asparagus can grow for 20 years of more, site selection is important. Asparagus crowns are planted in the spring, and the asparagus bed should be prepared in the fall. Plant the asparagus plants in a trench, spread out the roots and cover with soil. During the first year, don't harvest asparagus spears. Instead, allow the plants to develop a good root system. Burgess Seed & Plant Co. offers a wide selection of asparagus plants to buy online.