How to Grow Asparagus in Delaware

Asparagus (Asparagus officinalis) is a long-lived perennial vegetable that can thrive in Delaware’s climate with proper preparation and care. Once established, an asparagus bed can produce delicious, tender spears for up to 15-20 years, making it a valuable investment for home gardeners. Delaware’s mild winters and warm summers create favorable conditions for growing asparagus, though careful planning is essential to establish a healthy, productive asparagus patch.

1. Choosing the Right Asparagus Varieties for Delaware

  • Mary Washington: This is one of the most common and reliable asparagus varieties. It’s an open-pollinated variety with high yields and excellent disease resistance.
  • Jersey Giant: A popular hybrid variety known for its vigorous growth and high productivity. It is also resistant to common asparagus diseases like rust and fusarium.
  • Purple Passion: A unique variety with tender, sweet, purple-colored spears. It’s great for fresh eating and has a milder flavor than green asparagus varieties.

2. When to Plant Asparagus in Delaware

  • Planting Time: Asparagus is typically planted in the early spring (late March to April) in Delaware, as soon as the soil can be worked. The crowns (roots) should be planted in well-prepared beds for optimal growth.
  • Patience Required: Keep in mind that asparagus requires 2-3 years to fully establish before you can harvest a significant crop. The first couple of years focus on growing strong root systems.

3. Preparing the Soil

  • Soil Type: Asparagus prefers well-drained soil with a slightly alkaline pH (6.5-7.5). Heavy clay soils should be amended with organic matter or compost to improve drainage.
  • Site Selection: Choose a sunny location that will not be disturbed for years, as asparagus crowns are long-lived. The bed should receive at least 6-8 hours of sunlight daily.
  • Raised Beds: In Delaware’s areas with heavy soils or poor drainage, consider using raised beds to help prevent waterlogging, which can cause root rot.

4. Planting Asparagus Crowns

  • Trenching Method: Dig a trench about 12-18 inches wide and 6-8 inches deep. Space the crowns about 12-18 inches apart in the trench.
  • Positioning Crowns: Place each asparagus crown in the trench, spreading the roots out evenly. Cover the crowns with about 2 inches of soil, and gradually fill in the trench with soil as the plants grow.
  • Spacing: If planting multiple rows, space rows about 4-5 feet apart to allow the ferns (foliage) to grow without crowding.

5. Watering and Mulching

  • Watering: Keep the soil consistently moist during the first year to encourage strong root development. Once established, asparagus is drought-tolerant but will benefit from regular watering during dry periods.
  • Mulching: Apply a layer of mulch around the plants to retain moisture, suppress weeds, and regulate soil temperature. Organic mulch like straw or grass clippings works well.

6. Fertilizing Asparagus

  • Before Planting: Incorporate compost or well-rotted manure into the soil before planting. This provides essential nutrients for initial root growth.
  • Annual Fertilization: Each spring, apply a balanced fertilizer (10-10-10) or compost around the asparagus plants to promote healthy growth. Avoid over-fertilizing, which can cause excessive fern growth at the expense of spear production.

7. Managing Pests and Diseases

  • Common Pests: Asparagus beetles are a common pest in Delaware that feed on the spears and ferns. Hand-picking or using insecticidal soap can help control them.
  • Diseases: Rust and fusarium wilt can affect asparagus, but planting disease-resistant varieties like the Jersey series can help minimize problems. Maintaining good air circulation and not overwatering also reduce the risk of disease.

8. Harvesting Asparagus

  • Patience for First Harvest: In the first two years, avoid harvesting asparagus spears to allow the plants to establish a strong root system. By the third year, you can begin to harvest lightly.
  • How to Harvest: When spears are about 6-8 inches tall, cut them at ground level with a sharp knife. Harvest for about 4-6 weeks in the third year, extending the period in subsequent years to about 8 weeks.
  • Post-Harvest Care: After the harvest season, allow the ferns to grow, as they will feed the roots and help the plants store energy for the next growing season.

9. Winter Care for Asparagus

  • Fall Cleanup: In the fall, once the ferns turn yellow or brown, cut them back to the ground. This helps reduce disease and pest problems over the winter.
  • Mulching: Apply a layer of mulch to protect the crowns from freezing during Delaware’s coldest winter months. Remove the mulch in early spring before new growth emerges.

Conclusion

Growing asparagus in Delaware requires an initial time investment, but once established, this perennial vegetable will provide years of delicious harvests with minimal maintenance. By selecting the right variety, preparing the soil, and following proper care practices, you can enjoy fresh asparagus each spring for decades to come.