Grow Your Own Asparagus

Martie Young
Adams County Master Gardener

Asparagus grown in your own garden is infinitely preferable and much cheaper than any you can get at either the grocery store or even at a gourmet restaurant. Once you have eaten your own lightly steamed asparagus a few minutes after you have harvested it from the garden, you'll never go back. Asparagus is a delicious and dependable spring vegetable to grow.

Actually the best time to begin digging and preparing your asparagus bed would have been last fall, but don't wait another season; start now. Asparagus is a perennial vegetable. Once you plant it, your bed can last for 25 years. To have a fine bed of asparagus, plan carefully. If you haven't had a recent soil test, you should get one. Soil tests packets can be purchased at all extension offices.

Asparagus grows best in deep, well-drained, sandy loam soils. Soil pH should be maintained between 6.5 and 6.8. Asparagus does poorly at pH levels below 6.0. Your soil test will tell you what to add to get the desired pH. If your soil is heavy and crusts readily, incorporate generous amounts of well decomposed manure and/or organic matter. Early in spring when you can work the soil without it clumping (if the soil is too wet, you will end up with hard clumps of earth) dig your trench (double digging would be great) and add your fertilizer and lime, if needed, and organic matter.

It is important to note before going any further that the work that goes into establishing an asparagus bed doesn't pay off in good eating for two years. However, once established asparagus keeps coming back and getting better year after year.

About the end of March or in April you will be able to find asparagus crowns in the garden stores. They look like dried knots of roots, but this is what you want. Jersey Giant, Jersey Knight, Jersey King, Viking KB3 and/or Purple Passion grow well in Pennsylvania. The first four varieties are resistant to fusarium and rust. Purple Passion turns green when cooked. Buy 25 crowns for a 30-foot trench.

Plant the crowns in a trench at least 6-8 inches deep. Try to plant them on the north or east side of the garden where they will not shade lower growing plants. Spread out the roots of the crown with the bud up and lay in the trench (make a little mound in the trench to spread the roots on). The roots should be placed about 12 inches apart within the row, and rows should be 36 inches apart. Cover the crowns with 1 inch of soil. Soon you will see the asparagus sprigs appear. As the asparagus grows, carefully fill the furrow with soil. This forces the plant to grow tall before foliage appears. Furrows should be filled in by the end of the first season. In July, side-dress the plants with 5-10-10 fertilizer or compost. Spread fertilizer on either side of the asparagus and cultivate lightly into the soil.

Adequate soil moisture is important to asparagus culture, especially the first growing season. Wet the soil to 8 inches deep. By the second growing season, the plants will not require such frequent irrigation because of the deep and extensive root system. Thorough watering every two weeks will be sufficient. Also in the second season, you may need to lime in early spring to maintain the proper soil pH, plus add more 5-10-10 fertilizer or compost in July.

An important part of asparagus culture is allowing the ferns to mature during the first and second year. This green foliage, which can be very attractive, is needed to promote strong roots. Vigorous top growth in one season is the best assurance of good yield the next. In the fall the foliage turns an attractive yellow or gold. Winter weather will beat down the ferns. In early spring remove the plant residue from the bed to allow the new shoots to come up.

The plants have two full growing seasons before their spears are picked. This allows them to develop an adequate storage root system. In the third year when the spears appear in spring, you simply snap off (a knife is not necessary) the upper green, tender portion of all tight heads 7-10 inches long. Always harvest all spears that come up during the suggested harvest period. Allowing ferns to form early in the season robs the plant of energy that should be making mores spears.

The general rule for harvesting is the 2-4-8-week sequence. This means pick for 2 weeks the third year the plants are in the garden, 4 weeks the fourth year, and up to 8 weeks the fifth and following years. One 40-foot row of five-year-old asparagus will yield from 10-25 pounds of spears during the average season.

Asparagus can have pests, mainly the asparagus beetle. If you notice plant damage, check for shiny black specks on the speartips. The adult beetle is about 1/4 inch long and has a dark orange body with black spots. If you have mulch around your plants, pull it away from the base of the plants in early fall, since this is where grubs will over-winter. Planting tomatoes near asparagus can help with asparagus beetles, and parsley is also a good companion for asparagus.

Weeding is always an important chore. Hand weed because a hoe or tiller can easily damage the roots. A thick straw mulch will help keep down the weeds in summer.

Asparagus can be eaten raw directly from the garden or steamed until just barely soft. It is a significant source of Vitamins A and C. Although recipes for asparagus dishes abound, the best and simplest way to eat this delectable vegetable is to steam and add butter and maybe a little lemon juice squeezed over. Asparagus can be eaten cold or hot, in salads or pasta, with citrus or viniagrette, or in a very rich sauce.

Much of the information for this article comes from free PSU publications. Agricultural Alternatives: Asparagus Production geared to the small scale and part-time farmer is available at http://agalternatives.aers.psu.edu.

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