Growing

In the past, most garden asparagus has been started by planting crowns. Plant only healthy 1-year-old crowns and never use 2- or 3-year-old crowns. It is difficult to obtain commercial crowns free of Fusarium root rot (see discussion later in chapter). Fusarium carried on the seed will infect young seedlings and contaminate the garden permanently.

One way to avoid Fusarium is to plant asparagus seed that has been surface-sterilized. You can use this seed to grow your own crowns or seedling transplants.

Crowns are produced by seeding a nursery about 2 weeks before tomatoes are normally transplanted into the garden. Seed is sown 1 inch deep and 3 inches apart in the row with 2 1/2 feet between rows in the nursery. Plant 3 to 4 seeds for each crown you want to plant in the permanent bed. The following spring (February-March), when the plants are still dormant and the ground has thawed, carefully dig the crowns to minimize damage to the root system. Immediately plant the crowns in the permanent bed as described later.

To grow transplants, sow the seed 12 to 14 weeks before transplanting seedlings to the garden in the spring. The sowing date will vary from late December in the Southwest to mid-February in Northern areas of the country. Use a commercial potting mixture of peat moss and vermiculite, (pH 5.5 to 6.0) and sow two seeds 3/4 inch deep in small (2-inch diameter) pots, or seed in rows in flats. The rows should be 2 inches apart with seeds 2 inches apart in the row.

Maintain the temperature at 75 to 85 F while seeds are germinating. As seedlings emerge, they should grow at 70 to 75 during the day and 65 at night. Grow the plants in a greenhouse or window with full sunlight.

Use supplementary fluorescent lights to extend the day length to 12 to 14 hours when plants are not grown in the greenhouse.

Apply a soluble complete fertilizer, such as 15-15-15, at half the recommended rate 4, 8, and 12 weeks after sowing the seed. Rinse the foliage lightly with water after fertilizing to avoid fertilizer injury to the tender growth. Excessive fertilization promotes large tender tops and small root systems with limited reserves in the storage roots. Make the last application just before transplanting to the garden, after danger of the last killing frost is past. If you don't have a suitable place to grow your own seedling transplants, you may be able to get seedlings from a commercial plant grower who specializes in bedding plants.

Asparagus should be planted with other perennial crops for convenience of tillage and management. It is preferable to plant on the north or east side of the garden so as not to shade other vegetables or low-growing fruits.

Asparagus can be planted along a fence, as Iona, as there is plenty of sun. In fact, the beautiful green, fern-like foliage grows five to six feet high, and can be used as an ornamental summer screen. The female plants produce berries that become bright red in late summer and fall. The tops turn from green to an attractive yellow in fall and brown during winter.

Before planting, broadcast and turn under 1.2 pounds of 5-10-10 fertilizer (or equivalent) per 100 square feet of area. If lime is needed, turn it under along with the fertilizer. Keep a close check on soil pH, because asparagus does poorly at pH levels below 6.0.

Plant crowns with the buds up in the bottom of a 6-inch deep V-shaped furrow, and cover with 1 to 2 inches of soil. Plant seedlings 1 inch deep on small mounds in the bottom of a similar furrow. The seedlings will require some protection from water which may stand in the furrow and from soil which can wash into the furrow. Spacing for crowns and transplants is 12 inches apart within the row and 4 to 5 feet between rows. If only one asparagus row is planted, allow at least 3 feet between the asparagus and the closest other vegetable crop.

As the asparagus grows, carefully fill in the furrow with soil so as to avoid covering any asparagus foliage. The furrows should be filled in by the end of the first growing season. Side-dress the plants with 1.2 pounds of 5-10-10 fertilizer (or equivalent) per 20 feet of row in late July or early August. Spread the fertilizer on either side of the asparagus and cultivate it lightly into the soil.

Adequate soil moisture is important during the first growing season. Don't let the plants suffer for lack of water during dry weather. Weekly applications of irrigation sufficient to wet the soil 8 inches deep should be adequate.

After the first growing season, asparagus plants do not require frequent irrigation because of the deep and extensive root system. Thorough watering (2 inches of water) slowly applied every 2 weeks during dry weather is sufficient.

During early spring of the year after planting remove the brush (old stalks) and any over-wintering weeds. Broadcast lime as needed to maintain the proper soil pH plus 1.2 pounds of 5-10-10 per 100 square feet of bed. Sidedress another 1.2 pounds of 5-10-10 per 100 square feet in late July or early August.

Remove brush during each succeeding spring before the asparagus emerges, and broadcast lime if needed. At the same time spread 3.4 Pounds of 5-10-10 (or equivalent) fertilizer per 100 square feet of bed. Rake the fertilizer and lime 1 to 2 inches into the soil, taking care to avoid damage to the asparagus crowns.

Maintain good foliage growth for maximum photosynthesis. Tall weeds can shade asparagus and reduce photosynthesis. Even low weeds and grasses compete with the asparagus for water and nutrients. Thus, weed control is an important aspect of good asparagus culture. Chemical herbicides are toxic to many other vegetables and not recommended for the home garden.

Asparagus can be mulched with organic debris (leaves, grass clippings, etc.), but mulches can harbor pests, alter the soil pH, and change the crop's fertilizer needs. Clean cultivation of the asparagus is preferred.