Asparagus (Asparagus officinalis)
Related vegetables: Onions and related plants
- Herbaceous perennial. New shoots are harvested each year in spring, usually beginning in April, perhaps a bit earlier in southern Indiana. Plant in full sun.
- Tall, can reach a height of 6 ft.
- Dormant plants called crowns are planted in spring. There is a light harvest the following year and a full harvest, lasting 6-8 weeks, beginning the third or fourth year and thereafter. Estimated yield for a 10 ft row is 3-4 lb.
Purchase crowns and plant in spring after the soil has warmed to about 50 °F, beginning in April and continuing through late May. Loosen soil and correct any nitrogen, phosphorous, or potassium deficiencies, as indicated by a soil test. Dig a trench no more than 5-6” deep and at least 12” across. Place a high-phosphorus fertilizer (about 0.5 lb actual P/50 ft row) in the bottom of the trench to encourage root growth. Place crowns on the bottom of the trench. Crowns should be at least 18” apart in all directions. A distance of 5 ft between rows is often recommended.
Asparagus grows quickly and will fill in. Wide spacing improves airflow and reduces diseases. Fill the trench loosely with soil. Older references recommend adding soil gradually, 2 inches at a time, as the plant grows until the trench is filled but this is not necessary. You should see leaves in a week after planting. Irrigate as needed the year of planting. Do not harvest the first year. This allows the root system to become established.