Asparagus is a perennial vegetable grown for its delicious young shoots. Rich in B vitamins, vitamin C, calcium, and iron, asparagus is one of the first crops of spring harvest. Fresh-picked spears are far more tender and tasty than store-bought ones.
Asparagus thrives in any area having winter ground freezes or dry seasons. The mild, wet regions of Florida and the Gulf Coast are about the only places where it’s difficult to grow.
Select and prepare your asparagus bed with care; this crop will occupy the same spot for 20 years or more. It can tolerate some shade, but full sun produces more vigorous plants and helps minimize disease. Asparagus does best in lighter soils that warm up quickly in spring and drain well; standing water will quickly rot the roots. Prepare a planting bed about 4 feet wide by removing all perennial weeds and roots and digging in plenty of aged manure or compost.
Asparagus plants are monoecious—each individual plant is either male or female. Some varieties of asparagus, such as ‘Jersey Knight’ and ‘Jersey Giant’ produce all male or primarily male plants, so they’re more productive—male plants yield more harvestable shoots because they don’t have to invest energy in producing seeds. Choose an all-male variety if high yield is your primary goal. If you like to experiment, you may also want to grow an heirloom variety or a purple-stalked variety like ‘Purple Passion’. With an all-male variety, twenty-five plants are usually adequate for a household of four; plant double that amount for standard varieties. (Ardent asparagus lovers recommend tripling these quantities.)
Starting asparagus from 1-year-old crowns gives you a year’s head start over seed-grown plants. Two-year-old crowns are usually not a bargain. They tend to suffer more from transplant shock and won’t produce any faster than 1-year-old crowns. Buy crowns from a reputable nursery that sells fresh, firm, disease-free roots. Plant them immediately if possible; otherwise, wrap them in slightly damp sphagnum moss until you are ready to plant.
To plant asparagus crowns, dig trenches 12 inches wide and 6 inches deep (8 inches in sandy soil) down the center of the prepared bed. Soak the crowns in compost tea for 20 minutes before planting. Place the crowns in the trenches 1½ to 2 feet apart; top them with 2 to 3 inches of soil. Two weeks later, add another inch or two of soil. Continue adding soil periodically until the soil is slightly mounded above surface level to allow for settling.