Soil and Fertilization:

The ideal soil for growing asparagus is a deep, sandy loam. Soils which are too sandy do not have the capacity to hold enough water and plant nutrients, requiring the addition of manure or compost. Heavy clays are also not suitable for asparagus growth, as they have the tendency to become compacted, and they stay cold and wet later in the spring.

Because an asparagus planting will remain in the same location for 10 to 15 years, it is important to verify the fertility of the soil before the crowns are set. During the late summer of the year before the crowns are to be set, make a heavy application of manure, if available, and 5 pounds of 10-10-10 fertilizer for each 100 square feet. Spade or plow the manure and fertilizer into the soil to a depth of 10 inches. The soil should be tested for lime requirements the year before the crowns are set. Asparagus prefers a pH of about 6.5.

Planting:

It is best to obtain strong, well grown, one-year-old plants. The roots of the two-year-old plants are often seriously mutilated when dug. Plant in early to mid-spring when plants are still dormant. To set the plants, open a furrow 8 inches deep and 10 inches wide. If the layer of fertile soil is not 8 inches deep, then a more shallow trench must be dug. Loosen the soil in the bottom of the trench and leave it a little higher in the center. Place the crowns in the trench about 12-18 inches apart, taking care to spread roots uniformly. If more than one row is planted, have rows 4-6 feet apart. Cover the crowns with 1 or 2 inches of soil and firm well around the roots. When growth begins, fill soil gradually around the shoots and by mid-summer the trench will be completely filled.

Care During the First Year:

After the asparagus has been set, keep the area free of weeds. Let the stalks grow and stand over winter, as they will provide a mulch.

Care During the Second Season:

During the first part of March, old dead stalks should be cut down. Apply a good coat of well-rotted manure or compost as well as a 10-10-10 fertilizer (3 pounds for each 100 square feet of area) over and between the rows. The manure and fertilizer should be worked into the soil to a depth of 3 inches. Apply 2 pounds of nitrogen fertilizer for each 100 square feet of row at the end of June. Keep the planting free of weeds. Do not harvest any asparagus the second year.

Care During the Third Year (First Harvest Year):

Care as in second season. Increase the nitrogen application to 3 pounds per 100 feet of row. Harvest the asparagus spears when they reach 8 inches in length. Growth will soon become extremely rapid and harvesting will need to be done each day. Cut all spears for a period of about 4 weeks, then allow the spears to grow. If the soil is compacted at the end of the harvest period, rework as in the spring.

Care of the Established Planting:

Continue as in the third season. The harvest season can be lengthened to 6-7 weeks.

Harvesting:

Use a sharp knife and cut about 1 inch below the surface of the soil. Be careful to avoid knife injury to emerging stalks. Do not walk or step on the row during the harvesting process.

Pests:

The most important pests on asparagus plants are the common asparagus beetle and the spotted asparagus beetle. See GreenShare Factsheet on asparagus beetles for identification and control recommendations.

Adapted from the West Virginia University Extension, 2000

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For more information, call the URI CE Gardening and Food Safety Hotline at 1-800-448-1011 or (401)874-2929 from outside Rhode Island; Monday-Thursday between 9 am and 2 pm.

 

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