Asparagus is one of only a few perennial vegetable crops. It is a cold-weather plant that, once established, can live for 15 years. Asparagus, however, is not a plant for the impatient gardener.
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A good bed of asparagus can take three years to establish. However, for gardeners determined enough to fulfill the plant's needs, an asparagus bed can be an attractive addition to a garden as well as a long-lasting supply of delicious asparagus spears.
• Buying plants: Asparagus is planted as a "crown," which is a year-old plant root system. Each of these crowns, when mature, will produce about half a pound of asparagus spears each year.
• Location: Since asparagus plants have a long life span, it is important to pick a good location for your bed from the onset.
Asparagus plants prefer full sun. They do best in well-drained soil that is amended with compost or other organic materials.
Since the plants are very attractive, they sometimes are located to provide a decorative backdrop for the rest of the garden area.
• Preparation: Asparagus crowns can be planted in the spring as soon as soil is workable. They usually are planted "trench style," with the trench dug to about 10 inches wide and 7 inches deep.
This trench then is backfilled with a mixture of soil and compost to about 4 inches, leaving a 3-inch area at the top for placing each asparagus crown.
Crowns are laid on their sides about 12 inches apart. Soil placed over the crowns should remain loose, not packed down, and lightly watered.
As the plants mature, additional compost-rich soil gradually can be added around the base of each plant during subsequent seasons.
• Care: New asparagus plants require a light and regular supply of water.
A landscape drip system is ideal here in the Yampa Valley. Mature plants need less intervention and can tolerate periods of drought, though it is best to supply additional water during such times.
Plant beds should be kept free of weeds. After first planting and for an additional two years, asparagus can be lightly fertilized with a balanced fertilizer each spring. After the fourth year, the plants are not fertilized until after the harvest of the year's crop.
All ferns are cut down just before winter. Beds can be mulched over during winter, with mulch removed in early spring before spears emerge.
• Harvesting: For best results, asparagus is not harvested for the first two years following the planting. Instead, the plants are allowed to form attractive ferns that nourish the plant for subsequent growing seasons.
Harvest can begin the third year after planting as the spears emerge from the ground in the spring. Spears are cut off about an inch above ground level as soon as they reach a desirable size.
New spears continue to emerge and harvesting can continue for about a month. After this harvest period, new spears again are allowed to develop into ferns.
Estella Heitman is a Master Gardener through the CSU Extension Routt County. Call 970-879-0825 or email CSUMGProgram@co.routt.co.us with questions.