How to Grow Asparagus
Weeds and grass are the most common problems. Keep the area well-mulched and cultivated.
Salting to kill weeds is not recommended.
Asparagus (Asparagus officinalis) is a perennial and is the only vegetable that grows alongside roads and railroad tracks over a large part of the country. Asparagus takes three years to reach full production after being planted, but can be lightly harvested in the second year. Properly established asparagus can provide harvests for up to 25 to 30 years. Asparagus should be planted as soon as the ground is workable in the early spring. One-year-old crowns or plants are the preferable choice for planting, but it can be planted from seeds.
Choose the variety of asparagus you would like to plant. Asparagus plants can be male or female. Female plants can cause overcrowding due to the amount of energy they require to sprout new seedlings. Male plants have thicker and larger spears. See the Resources section below for a variety listing.
Plan a good bed preparation in a place that will get good drainage and part or full sun. Account for the fact that the asparagus ferns may shade other nearby plants. Prepare the bed as early as possible. The soil can be enriched with manure, compost, bone or blood meal, leaf mold or any combination of these preparations. Asparagus can thrive in slightly acidic soil (pH of approximately 5.8 to 6.5) and in alkaline conditions (up to 9.0). The crowns will need to be spaced 9 to 12 inches apart, so allow proper spacing for the amount of asparagus you plan to plant.
Till the area to remove all weeds. Dig a trench that is approximately 12 to 18 inches wide and 6 inches deep. Leave 4 to 5 feet between trenches. Draw a hoe alongside each trench so that it forms a mound of soil in the center, running along the length of each trench.
Soak the crowns briefly in lukewarm water before planting. Spread them evenly, 18 inches apart, with the crown bud side up. Make sure they are placed in an upright, centered position. Drape the roots over the sides of the trench. Cover the crowns 2 inches deep with a combination of one part compost to three parts topsoil. Water the bed thoroughly. You can add more soil to the trench after a month or so, when the shoots appear.
Water the beds frequently during their first year, being careful not to disturb the roots. Asparagus tends to rise closer to the soil surface as it matures, so you can add more topsoil as needed. Spread a 4 to 6-inch layer of mulch around the base of the plants. Cut down any dead foliage in late fall. Cultivate lightly and keep mulch topped off during the second year and beyond.
Begin harvesting lightly in the spring of the second year. Harvest asparagus whose spears are thicker than a pencil the third year and beyond. You can cut the spears right at ground level when they are 6 to 8 inches tall.