Asparagus

BOTANICAL NAME:

Asparagus officinalis

COMMON NAMES

asparagus

FAMILY

Liliaceae, the lily family

PLANT DESCRIPTION

Asparagus is a herbaceous perennial, with both male and female plants. Asparagus plants are ferny and grow to 1.5 m.  Asparagus is usually considered a temperate plant but it is easy to grow in a subtropical climate as it thrives on the rain and has no problems with pests or diseases. In fact, in old, abandoned gardens, asparagus can be seen growing years later amongst tall grass and weeds.

USES

Asparagus is an edible delicacy and can be eaten raw or cooked.

PLANTING DETAILS

Asparagus Crown

Asparagus Crown

Asparagus prefers the pH of the soil should be 6.5 – 7.0, lime if necessary.  Plant in full sun in a well-drained soil. Thorough preparation of the soil is needed as asparagus crowns are long-lived and are heavy feeders. Dig deeply, or if possible double dig the trenches and incorporate generous amounts of compost and well-rotted manure into the soil. In heavy clay soils deep digging should be avoided as it will make drainage worse, in this case beds should be mounded and gypsum applied.Plant in winter or early spring, while the crowns are still dormant. Plant in furrows that are at least 20 – 30 cm deep (the deeper the better) and 30 cm wide. Backfill with compost to a depth of 7.5 cm. Place the crowns onto a small mound in the centre of the furrow, so that the roots point down at about 45°, spread the roots out carefully. Space the plants 45 cm apart, with 1.2 m between rows. Fill in the furrow gradually as growth progresses.

ANNUAL CARE

Asparagus berries from a female plant

After the first frost in winter or when the foliage browns off, cut off the old tops about 7.5 cm from the soil surface. Try to keep the berries from falling on the ground, as they will germinate and choke the bed. Apply a generous dressing of compost and well-rotted manure to feed the bed for its spring flush of growth. Then top with a thick hay mulch.

If nore plants are required the crowns can be divided after 3 years, this should be done during the dormant winter period.

HARVEST

Asparagus spears must be harvested every 24 hours. At the height of its growing season, in warm humid conditions, single spears of asparagus can grow over 2 cm in one hour. Care should be taken to harvest very lightly the first year after planting, to allow the crowns to build strength. In subsequent years in cool areas stop cutting spears in late spring; in subtropical areas it is usually possible to harvest a second time during the wet season. Cut the spears carefully to avoid injuring the crown. As a rule-of-thumb, if the spears are thicker than a pencil cut them before the spears branch, usually at approximately 20 cm high, if they are skinnier, leave them to develop and feed the crown.

NUTRITIONAL INFORMATION

Asparagus is nutrition packed, and supplies a range of B group vitamins, vitamin C and potassium.

In herbal medicine Asparagus is considered to have a cleansing effect on both the liver and kidneys.

COMPANION PLANTING

Asparagus companion planting table

Asparagus companion planting table