Asparagus (Asparagus officinalis L. var. altilis)-Hort Answers - University of Illinois Extension
University of Illinois Extension

University of Illinois Extension

Hort Answers


Asparagus officinalis L. var. altilis

Emerged harvested asparagus spears
Emerged harvested asparagus spears

Asparagus is a hardy perennial. It is the only common vegetable that grows wild along roadsides and railroad tracks over a large part of the country. Although establishing a good asparagus bed requires considerable work, your efforts will be rewarded. A well-planned bed can last from 20 to 30 years. For this reason, asparagus should be planted at the side or end of the garden, where it will not be disturbed by normal garden cultivation. Asparagus is one of the first vegetables ready to harvest in the spring. Asparagus is native to the Mediterranean and was eaten by the ancient Greeks.

As asparagus plants grow, they produce a mat of roots that spreads horizontally rather than vertically. In the first year, the top growth is spindly. As the plants become older, the stems become larger in diameter. As noted, asparagus plants are dioecious (either solely male or solely female). The female plants develop more spears or stems than the male plants, but the stems are smaller in diameter. With normal open-pollinated varieties, gardeners plant both male and female plants in an approximate ration of 1:1. After the first year, small red berries form on the female plants in late summer. These then fall to the ground, sprouting plants that essentially become perennial weeds in the asparagus bed. Following freezing weather in the fall, the asparagus tops should be removed to decrease the chances of rust disease overwintering on the foliage.

Because asparagus remains in place for years, advance soil preparation helps future production greatly. Working green manure crops, compost, manure, or other organic materials into the proposed bed well in advance of planting is a good approach.

Asparagus should be fertilized in the same way as the rest of the garden the first 3 years. In the spring, apply 10-10-10, 12-12-12 or 15-15-15 fertilizer at the rate of 20 to 25 pounds per 1,000 square feet of area or 2 pounds per 100 square feet and incorporate with soil tillage. Starting in the fourth year, apply the same amount of fertilizer but delay application until June or July (immediately after the final harvest). This approach encourages vigorous growth of the "fern," which produces and stores nutrients in the roots for next year's production season. Weeds and grasses are the worse problems with asparagus. They compete with the developing spears, make an unsightly area in the garden and significantly decrease yield and quality. Start frequent, light, shallow cultivation early in the spring in both young plantings and mature patches that are being harvested.

The list of commonly available varieties has significantly changed in recent years. Standard varieties like Mary Washington, Martha Washington and Waltham Washington are still being offered; but a number of new varieties that are either predominantly or all male recently have been introduced in to common usage. Asparagus plants are naturally either male or female. The female plants bear seeds, which take considerable energy from the plant and sprout new seedlings, which cause overcrowding in the bed. Male plants produce thicker, larger spears because they put no energy into seeds and have no weedy seedling problem. A line that produces only male plants was discovered and has been incorporated into some truly amazing varieties. Jersey Giant, Jersey Knight, Jersey Prince, Syn 53, Syn 4-362, UC 157 and Viking KBC are new hybrids with larger yields. It is advisable to plant the best variety available, as an asparagus bed should remain productive for at least 15 to 20 years. If you are starting a new bed, you may never get to choose a variety again if your bed produces that long. All the newer varieties are cold tolerant and are resistant to rust and fusarium wilt. 
Planting Time
Very hardy - early spring as soon as the ground can be worked


Harvest Time


Crowns planted in 12-18 inches wide trenches & planted 6 inches deep, 9-12 inches a part


Soil Conditions
Moist, Well-Drained
Exposure/Light Requirements
Full Sun
Pests and Problems

Environmental Damage

Fungal Disease

Herbicide Injury

Insect Damage

Additional pests and problems that may affect this plant:


  • Asparagus aphid
  • Twelve-spotted-asparagus beetle
  • Pigweed case-bearer
  • Cutworm
  • Tarnished plant bug
  • Thrips


  • Fusarium wilt and crown rot (Fusarium oxysporum and F. moniliforme)
  • Gray mold (Botrytis spp.)
  • Phytophthora crown and spear rot (Phytophthora spp.)
  • Viraldiseases

Storage problems:

  • Chilling injury
  • Bending and elongation
  • Feathering
  • Low oxygen injury
Additional Notes
Asparagus should be planted as soon as the ground can be worked in the spring. One-year-old crowns or plants are preferred. Seeds are sown in a production bed and allowed to grow for a year. The young plants have compact buds in the center (crown), with numerous dangling, pencil-sized roots. Adventurous gardeners can start their own plants from seed. Although this adds a year to the process of establishing the bed, it does ensure fresh plants and the widest possible variety selection. Asparagus can be harvested the third year after planting crowns, but for no more than one month the first season. The plant is still expanding its root storage system and excessive removal of spears weakens the plants. During the fourth year and thereafter, the spears may be harvested from their first appearance in the spring through May or June (as long as 8 to 10 weeks). Harvest spears 5 to 8 inches in length by cutting or snapping. To cut a spear, run a knife into the soil at the base of the spear and carefully sever it. Because the spear is cut below the point where fiber develops, it becomes necessary to remove the fibrous base from the tender stalk. Cutting may damage some spear tips that have not yet emerged from the ground. To snap a spear, grasp it near the base and bend it toward the ground. The spear breaks at the lowest point where it is free of fiber. Either method is acceptable. Cutting is often preferred by commercial growers and snapping by home gardeners. Asparagus deteriorates rapidly after harvest. If it is not eaten immediately, it should be processed or refrigerated.


Related Resources
Home, Yard & Garden Pest Guide
U of IL - Distance Diagnosis through Digital Imaging
U of IL - Plant Clinic