The Age Of Asparagus

By Elaine Homstad, Fairfax Master Gardener
Q. What did one vegetarian hippie say to the other?
A. “This is the dawning of the Age of Asparagus!”
Asparagus, of course, is no joke. It is one of the most nutrient-rich and delicious vegetables available. Although in the past it could only be found fresh in stores and farmers markets in the spring, now you can buy it fresh in stores year-round. But have you ever tried growing your own? If you are a patient gardener who is willing to delay gratification for long-term results, you might like to try. If so, here are some “Asparagus Tips” for you.

harvested asparagusAsparagus, unlike many other vegetables, is a perennial, and, true to a perennial’s nature, is best after its second year. An asparagus bed can last from 12 to 15 years, so if you are planning one, make sure that it can remain undisturbed for a long time.

Asparagus needs a sunny location, with at least six hours of full sun per day. It prefers well-drained, deep and loose soil. Aim for a neutral soil pH (6.5 to 7.0) and ensure the soil’s ideal conditions with an enrichment of organic materials such as manure, compost, leaf mold, sand, peat moss or a combination of these. It is important that if your soil has a heavy clay composition, the soil should be made loose and friable, which may require double digging.

asparagus plant

Asparagus plant

Preparation for planting is of course very important. You will need to have a deep trench 12 inches wide by 12 inches deep ready for your plants, which can go into the ground in March or early April, a few weeks before the last expected frost. Although they can be grown from seed, it is much more practical to plant 1- to 2-year-old crowns. For our area, the most reliable varieties are Jersey Knight and Jersey King, which are all-male plants with good resistance to rust and fusarium crown and root rot. Put about 2 inches of soil in the bottom of the trench, add the plant while spreading out the roots, and cover with another 2 inches of soil. Gradually add more soil as the plant grows (about every two weeks) until the trench is filled. Follow the grower’s instructions on planting depth, as it may be different based on the variety grown. Plants should be spaced 15 to 18 inches apart. Water after planting, and keep soil moist, but not soaked. Water at ground level, using drip irrigation if possible, rather than from above.

Asparagus sprouts

Asparagus sprouts

Asparagus is a medium-heavy feeder, so plan to top-dress your bed with compost in mid-February to mid-March every year. Fertilize with a balanced (5-10-10) fertilizer in the early spring, before the plants send up shoots, and then again in mid-July to mid-August. The beautifully airy fern-like foliage that appears once the harvest time is over is what the plant needs to develop a strong root system and food stores in order to survive and thrive. The feathery foliage also makes it a nice plant to incorporate into a flower bed!
One plant will yield about 10 to 20 spears per season, but you will not realize that harvest until at least their third year. DO NOT harvest at all in the first year, and in the second year, harvest only lightly — about 50 percent of the spears for only three to four weeks. By the third year, your plants should be well established, and you can usually harvest daily for eight to ten weeks. Harvest when spears are no taller than 8 inches and snap them off just below the soil surface.

It is important to keep weeds from appearing in the bed, and hand-pulling is preferable to hoeing, to avoid disturbing the plants. Should asparagus beetles appear, they should be hand-picked, rather than sprayed. The bed should also be kept mulched with a seed-free straw, hay, grass clippings or shredded leaves rather than with a wood-based mulch.

References
Asparagus, Virginia Cooperative Extension Publication 426-401
Growing Guide – Asparagus, Cornell University
Asparagus, University of Maryland Extension Publication GE 100

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