GARDENER'S READING ROOM
Edibles

Perennial Vegetables

Gardeners who want some permanence in their vegetable garden, consider Asparagus, Artichokes or horseradish! You will find asparagus and horseradish roots in late winter. Artichoke plants are usually available early to mid summer.

Asparagus gives the first taste of homegrown vegetables in the spring. Plant now for crops next year. Because asparagus is a long-lived plant (10-15 years) it is well worth the effort to prepare a rich loose bed separate from your vegetable garden. Choose a sunny area with rich highly organic soil. Dig a trench 1 foot wide and 6-8 inches deep. Heap loose soil enriched with manure or compost to about 3 inches below the top of the trench. With our wet winters we recommend you not plant any deeper. Spread the roots out evenly, spacing them about 1 foot apart. Cover with 2 inches of soil. As the plant grows, fill in the trench. This spring let the roots grow without any harvesting. Next year you can harvest stalks for about 4 weeks. Each year after that your harvest time and quantity of spears will increase. Allow a dozen plants per asparagus-loving family member.

To keep your asparagus patch healthy, use a high-nitrogen fertilizer twice a year. Keep the bed well weeded and watered.

Asparagus Varieties:
Mary Washington
*standard commercial variety
*resistant to rust
*60 day cutting season
*long straight spears with tight tips

Jersey Knight
*male hybrid
*high yielding
*excellent fusarium and rust resistance
*longer lived than Mary Washington

Sweet Purple
*deep burgundy color
*20% higher sugar content than green varieties
*mild, nutty flavor
*tender spears, less stringy, entire spear can be used with little waste

Horseradish
This perennial produces a thick aromatic root with medicinal properties, often served with roast beef. Early in spring, plant cuttings in a vertical position with the larger end upward. Cover them with 1 to 2 in. of soil. Thicker roots are more desirable because they yield a larger taproot in the fall. Adequate moisture results in optimum yields, but the plants will produce edible roots with minimal watering. If your soil is good, fertilizer is not needed. Excessively good growing conditions encourage horseradish to spread. To contain horseradish in a small garden you may want to plant the roots into a bottomless black plastic pot buried in the ground.

Most of horseradish's root growth occurs in late fall, so delay harvesting until late September. At this time carefully dig around the plant. There will be many lateral roots attached to the taproot. The taproot can be stored in a cold room like potatoes and used anytime. The lateral roots are used for root-cuttings for next year's crop. Pull up most of the lateral roots to minimize the number of horseradish plants in your garden.

Artichokes
Artichokes can grow 4-6 feet tall and wide. In the NW choose a sunny location and give each plant plenty of room to flourish. Provide rich, loose, well-drained soil. Artichokes can be grown in rows or used in the landscape for foliage interest. Each plant sends up seasonal shoots, from a single shoot in young plants to as many as 12 or more in established plants. Each shoot forms a cluster of large silvery to sage-green leaves from which a center stem grows. The artichokes are produced on the elongated stem and on side branches. The top bud is usually the largest; harvest all the buds when top bud is 2 to 4 inches in diameter. Or for a very special treat, harvest them smaller (and bring them to me)!

After harvest, cut back old bearing stalks to ground and mulch with rotted manure or feed with a balanced fertilizer. During the growing season, apply nitrogen fertilizer monthly. In late fall, mulch with leaves or compost to protect the plant from cold.

By Sarah Garrison
Skylights Spring 2003 Vol 17, No. 1

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