Asparagus as an Early Season Crop

Asparagus is the earliest spring vegetable for most Nebraska gardeners and a high value garden crop. It’s a delicious and nutritious food, and with proper care, an asparagus planting can be productive for 20 or more years.

Asparagus is normally planted from dormant, 1-year old crowns. All-male varieties of asparagus, including Jersey Giant, Jersey Knight, Jersey Prince and UC 157 have been shown to out-produce traditional female varieties such as Mary Washington or Martha Washington by 3 to 1. Female varieties put considerable energy resources into seed development, reducing their spear production. Plus the self-seeding of new plants can cause overcrowding in the asparagus bed. Male plants produce thicker, larger spears and do not produce seed. The newer male varieties are also resistant to Fusarium and rust, and have good cold tolerance.

Choose a garden site with well-drained soil, and full sun. Since asparagus is a perennial that will stay in place for many years, advance preparation of the soil will greatly increase future production. Prepare the soil by incorporating 50-100 pounds of manure and 3-4 pounds of 10-10-10 fertilizer per 100 square feet of planting bed. Plant the crowns 12- 18 inches apart in trenches spaced 5 feet apart. In sandy soils, the trench should be 6 inches deep, but only 4 inches deep in heavier soils. (Research has shown that the deeper asparagus is planted, the more yield is reduced.) Place the crowns in the trenches and fill the trenches with 2- 3 inches of soil. As the plants grow, gradually add more soil until the trenches are filled.

Asparagus spears should not be harvested during the first year while the bed is becoming established. Harvest lightly for only 3 to 4 weeks the second year. In subsequent years, harvesting can begin when the newly emerging spears reach 6-8 inches tall, usually about mid-April in eastern Nebraska, and continue for 6 to 8 weeks. Remove the spears by cutting or snapping them off at the soil surface.

If weeds are a problem in an existing asparagus bed then when finished harvesting, snap all the spears off slightly below ground level. Make an application of glyphosate to the asparagus bed to kill any existing weeds. New asparagus spears will appear and should be allowed to remain throughout the summer. An application of mulch will help to prevent the germination of any additional weeds.