Asparagus officinalis (Liliaceae)
Asparagus is a long-lived perennial. Its tender young shoots are one of the first vegetables ready to harvest in the spring.
Asparagus is hardy in Zones 2-9. It thrives in any area with winter ground freezes or a dry season to provide a dormant period each year. Asparagus does best in full sun and deep, well-drained soil. Select a permanent location carefully, since plants will produce for 20 years or more. Dig out all weeds and add plenty of compost to the soil before planting. Asparagus requires high levels of phosphorus, potassium, and nitrogen. Do a soil test and add amendments as necessary. If your soil is heavy or poorly drained, plant asparagus in raised beds.
Plant 1-year-old crowns from a reputable nursery that sells fresh, firm, disease-free roots, or start your plants from seed. Soak seeds or crowns in compost tea for 5 minutes before planting to reduce disease problems.
Most seed-grown asparagus plants eventually out-produce those started from crowns. Growing from seed also allows you to eliminate female plants. A bed of all male plants can produce as much as 30 percent more spears than a mixed bed of male and female plants. Plants grown from seed will flower their first summer. When the tiny flowers appear, observe them with a magnifying glass. Female flowers have well-developed, 3-lobed pistils; male blossoms are larger and longer than female flowers. Weed out all female plants. The following spring, transplant the males to the permanent bed.
Harvesting new plantings too soon can stress plants and make them more susceptible to pest problems. Harvest for 2 weeks the second season, 4 weeks the third season, and up to 8 weeks thereafter.
Mulch with a high-nitrogen compost each spring before spears emerge, and again in fall. Leave winter-killed foliage, along with straw or other light mulch, on the bed to provide winter protection. Remove and destroy the
foliage before new growth appears in the spring: it can harbor diseases and pest eggs. Over the years, the crowns will push closer to the soil surface, resulting in smaller and less-tender spears. To remedy this, mound 6" of soil over the rows each spring.
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