This is an archived article that was published on sltrib.com in 2005, and information in the article may be outdated. It is provided only for personal research purposes and may not be reprinted.
Asparagus is one of the few popular vegetables that are perennial plants. Every spring, asparagus sends up new stem shoots from root systems. These spears are harvested for up to eight weeks, depending on the plant maturity.
A few years after planting, 20 asparagus plants can provide an average family with enough spears for fresh consumption and preservation.
Considering the price of asparagus in the store and the superior quality of truly fresh asparagus, starting a bed of asparagus in your back yard is worth considering.
Recommended asparagus varieties for Utah include Jersey Giant, Jersey Knight, UC157 F1 and Purple Passion. Although commonly found in the seed rack, Mary Washington is no longer a recommended variety for Utah.
Asparagus is usually planted as 1-year-old crowns, which may be bought from seed catalogs or some garden centers during early spring. Good crowns should have eight to 10 large roots and a healthy bud cluster.
Soil preparation is critical to successful establishment of an asparagus bed. One hundred square feet can support about 20 plants. Asparagus prefers full sun most of the day and good soil drainage. In late summer the year before planting asparagus, kill all existing vegetation in the bed area. Pay special attention to perennial weeds.
Apply well-composted organic matter about 3 inches deep over the entire bed, plus one-half pound of high phosphate fertilizer (11-52-0), then rototill or dig in the amendments at least 6 inches deep.
Dig a trench 8 inches deep, then place the crowns in the trench about 12 inches apart. Cover the crowns with 2 inches of soil. Irrigate, preferably by drip system, about 1 to 2 inches per week. More soil may be added over the crowns as they grow, but don't cover living leaves. Maintain the same irrigation schedule the next year.
Begin harvesting during year three. Snap spears off at their base when they are 6 to 8 inches tall. During year three and four, harvest for up to four weeks.
Starting in year five, harvest for up to eight weeks. Once harvest time has passed, fertilize with a complete fertilizer (16-16-16) unless soil tests indicate otherwise.
As summer passes, allow asparagus to fern out, grow leaves and replenish the root system with energy produced by photosynthesis. Freezing temperatures in late fall will kill the leaves and stems. Next spring before the new spears push up, clear off the dead fern with a weed-eater or scythe.
During the first three years, irrigate 1 to 2 inches every week. After that, water as needed. Because asparagus is a perennial plant, the root system can be extensive. Water less frequently but more deeply than you water annual vegetables.
Expect good asparagus production for up to 15 years. Past that time, productivity drops off and the area should be rotated into a different crop.
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Maggie Wolf is an assistant professor for USU Extension in Salt Lake County. E-mail her at maggiew@ext.usu.edu.
Growing asparagus
Asparagus is a good early spring vegetable for most gardens. For more information about growing asparagus in Utah, visit the USU Extension Web site at http://extension.usu.edu/files/factsheets/asparagus.pdf