Asparagus

Asparagus is established from dormant one-year-old crowns or from seed, planted in a dedicated, undisturbed bed with full sun and well-drained, organic soil at a neutral pH. Crowns are set in a trench 6 to 18 inches deep, spaced roughly 12 to 18 inches apart with rows several feet apart, then gradually backfilled as spears emerge through the season; seed-grown plants need an extra year to reach the same stage.

Because the plants are dioecious, male plants are generally favored since they avoid producing berries and seedlings that can crowd the bed, while female plants channel more energy into fruit than spears. During the first growing season the crowns need thorough, regular watering while roots establish; mature plantings tolerate some drought but benefit from about an inch or two of water weekly in dry spells, with irrigation withheld in early autumn to encourage dormancy.

Weeding is done by hand or shallow cultivation before spears emerge in spring to avoid injuring the crowns, followed by mulch to suppress further weeds and conserve moisture. Nitrogen or balanced fertilizer is applied in early spring during establishment and, once the bed matures, again after harvest ends; a yearly top-dressing of compost is also beneficial. After the harvest window closes, the spears are left uncut to grow into tall, fern-like foliage that feeds the roots for the next season, and this growth is cut down to short stubs only after it yellows with frost.

Asparagus beds are commonly troubled by asparagus beetles, spotted asparagus beetles, and aphids, alongside diseases such as fusarium, rust, crown rot, and needle blight. Choosing resistant varieties and removing old foliage after it dies back in fall are recommended ways to limit these problems, and drip irrigation rather than overhead watering helps keep disease from taking hold on wet foliage.

Handling the raw young shoots can cause contact dermatitis, so gloves are advised, and the plant's berries and stems carry a low level of toxicity that can cause gastrointestinal upset if the berries are eaten.

Harvest is delayed for the plant's own benefit: no spears are cut the first year after crowns are set, only a light harvest of a few weeks is taken in year two, and full harvesting of six to ten weeks or more begins from the third or fourth year onward as the root system matures. Spears are picked daily through the harvest window once they reach about five to nine inches tall, either snapped by hand at the base or cut just below the soil line, taking care not to injure the crown buds that will produce later spears.

Once cut, spears are best used or refrigerated right away, commonly wrapped or bagged to retain moisture, and the crop also freezes well for longer storage.

Culinary: Asparagus spears are eaten as a fresh vegetable, typically steamed, boiled, grilled, or roasted, and the crop is also well suited to freezer storage for use beyond the short spring season.

Ornamental: Beyond the table, established plants are valued in the garden for their soft, feathery, fern-like summer foliage and, on female plants, showy red berries, making asparagus a border or accent plant as well as a food crop.

Medicinal: Early Roman, Greek, and Egyptian cultivators used asparagus for medicinal as well as food purposes, a use reflected in the species name, which refers historically to the plant's sale and use as a medicinal herb.

Asparagus is believed to be indigenous to parts of Russia, the Mediterranean region, the British Isles, and parts of Africa. It was first brought into cultivation by the early Romans, Greeks, and Egyptians, and was already being grown in England more than two thousand years ago.

Early colonists carried asparagus to North America, though it was not planted extensively by commercial growers there until after 1850. The species has since naturalized beyond cultivation in the United States, often found growing along roadsides and ditches.