Q. How do I grow asparagus?
Asparagus can be grown from seed, but it is best to start with one- or two-year-old plants (crowns). Asparagus prefers neutral soil, so test your soil before planting and add lime to get a pH of about 7. Add a phosphorus and potassium–rich fertilizer or decayed manure at the same time.
Asparagus prefers full sun but will grow in part shade. Mid-April to mid-May is a good time to plant. Dig a trench about a foot wide and no more than 5-6 inches deep. Place the plants in the trench about 1 foot apart and cover them loosely with soil to the original bed level. Spears should appear in one or two weeks. Hill soil around the stems as they grow. Mulch the plot in mid-summer and add compost or well-rotted manure periodically. Water only during dry spells, as asparagus does not tolerate wet soil.
To allow the plants to get well established, do not harvest spears during the first year. You can harvest a few stalks per plant in the second year and then more heavily in future years. Asparagus beds will continue to thrive for 15-20 years if well taken care of.
Weeds can be a big problem in asparagus beds. Mulch will help to keep down weeds. Also hand-weed periodically to prevent weeds from taking over your asparagus plot. Asparagus beetles may invade your plants. Hand-pick them if you want to avoid using insecticides.
It is preferable to use newer, all-male hybrids rather than the old Mary Washington varieties as these are more productive and easier to maintain. Popular varieties are Jersey Giant, Jersey Prince and Jersey Knight. The Giant variety is best for colder regions.
Harvest your asparagus when the spears are 7-9 inches long and still have tight tips. They should be snapped, not cut with a knife. The harvest period can last for 4-8 weeks depending on the climate and weather. Stop harvesting when the tips get thin and small. Asparagus is very perishable and should be harvested in early morning. The spears can be stored in plastic bags in the refrigerator for 1-2 weeks. Enjoy!
Many nurseries carry asparagus crowns. They can also be ordered from mail order companies, for example Nourse Farms.
For tips on a variety of gardening topics, see our Plant Information Guides.
- Courtesy of NYBG Plant Information Service