How to Raise Asparagus?
Asparagus cultivation involves planting crowns in well-drained soil, providing consistent watering and fertilization, and patiently waiting for the plant to establish before harvesting; this process guarantees a delicious and perennial vegetable crop for years to come.
Why Grow Asparagus?
Asparagus, Asparagus officinalis, is a perennial vegetable prized for its tender spears that emerge in the spring. Growing your own asparagus offers several advantages over purchasing it from the store. First, the flavor is undeniably superior. Freshly harvested asparagus possesses a sweetness and delicate texture that degrades quickly after picking. Second, asparagus plants are long-lived, often producing for 15-20 years or more with proper care. Third, you gain control over the growing practices, ensuring that your asparagus is grown organically and free from harmful pesticides. Finally, the act of harvesting your own food provides a deep sense of satisfaction and connection to nature.
Selecting the Right Asparagus Variety
Choosing the right variety of asparagus is crucial for success. While ‘Mary Washington’ was once a standard, modern cultivars offer improved disease resistance and higher yields. Some popular choices include:
- ‘Jersey Knight’: An all-male hybrid known for its vigor and disease resistance. All-male varieties produce more spears since they don’t expend energy on seed production.
- ‘Jersey Giant’: Another all-male hybrid similar to ‘Jersey Knight’, but potentially more suited to warmer climates.
- ‘Millennium’: A widely adapted hybrid with excellent spear quality and productivity.
- ‘Purple Passion’: Offers uniquely colored, sweeter spears that turn green when cooked.
Consider your climate and soil conditions when selecting a variety. Local nurseries can provide recommendations based on your specific region.
Preparing the Asparagus Bed
Asparagus requires a well-drained, fertile soil with a pH between 6.5 and 7.0. Proper bed preparation is essential for long-term success.
- Soil Testing: Begin by conducting a soil test to determine the pH and nutrient levels. This will guide your amendment choices.
- Weed Removal: Eliminate all perennial weeds from the planting area. Asparagus is a slow grower and cannot compete effectively with weeds.
- Amendment: Amend the soil with plenty of organic matter, such as compost or well-rotted manure. This improves drainage, fertility, and water retention. Incorporate lime if the soil pH is too low.
- Trenching: Dig trenches that are 12-18 inches wide and 6-8 inches deep. The spacing between trenches should be 4-5 feet.
Planting Asparagus Crowns
Asparagus is typically planted from crowns, which are one-year-old bare-root plants.
- Crown Selection: Choose healthy crowns with plump, radiating roots. Avoid crowns that are dry or damaged.
- Spacing: Plant the crowns at the bottom of the trench, spacing them 12-18 inches apart.
- Covering: Gently spread the roots and cover the crowns with 2-3 inches of soil.
- Gradual Filling: As the asparagus spears emerge, gradually fill in the trench with soil until it is level with the surrounding ground.
Asparagus Care: Watering, Fertilizing, and Weeding
Proper care is crucial for establishing a healthy asparagus bed.
- Watering: Water regularly, especially during dry periods. Asparagus needs consistent moisture, particularly during spear production.
- Fertilizing: Fertilize in early spring and again after the harvest season. Use a balanced fertilizer or a side dressing of compost.
- Weeding: Keep the bed free of weeds through hand-pulling or shallow cultivation. Avoid using herbicides, as they can damage the asparagus plants.
- Mulching: Apply a layer of organic mulch, such as straw or wood chips, to suppress weeds, conserve moisture, and regulate soil temperature.
The Patience Game: Waiting for the Harvest
The most challenging aspect of growing asparagus is the initial waiting period.
- First Year: Do not harvest any spears during the first year. Allow the plants to focus on developing a strong root system.
- Second Year: In the second year, you can harvest a few spears, but limit the harvest to a couple of weeks.
- Third Year Onward: From the third year onward, you can harvest spears for 6-8 weeks each spring.
Harvesting Asparagus Spears
Asparagus spears are ready for harvest when they are 6-8 inches tall and the tips are still tightly closed.
- Cutting: Use a sharp knife or asparagus knife to cut the spears at or slightly below the soil surface.
- Timing: Harvest in the morning when the spears are firm and crisp.
- Frequency: Harvest every day or every other day during peak production.
Common Asparagus Pests and Diseases
While relatively resistant, asparagus can be affected by certain pests and diseases.
| Pest/Disease | Symptoms | Control |
|---|---|---|
| Asparagus Beetle | Chewed spears and foliage. | Handpick beetles and larvae. Use insecticidal soap. |
| Asparagus Rust | Orange or reddish-brown pustules on spears. | Plant resistant varieties. Ensure good air circulation. Fungicides. |
| Crown Rot | Yellowing foliage, stunted growth. | Improve drainage. Remove and destroy infected plants. Crop rotation. |
| Fusarium Wilt | Yellowing and wilting of spears. | Plant resistant varieties. Avoid planting in heavily infested soils. |
Preparing Asparagus for Winter
Once the harvest season is over, allow the asparagus ferns to grow and mature. These ferns will nourish the root system for the following year’s growth. In the fall, after the ferns have turned brown, cut them down to the ground level. Mulch the bed to protect the crowns from winter cold.
FAQs: Your Asparagus Questions Answered
How long does it take for asparagus to mature?
Asparagus requires patience. While the crowns can be planted in the spring, it takes 2-3 years before you can harvest a substantial crop. This allows the plants to establish a strong root system.
What kind of soil is best for asparagus?
Asparagus thrives in well-drained, sandy loam soil that is rich in organic matter. Heavy clay soils should be amended with compost and other organic materials to improve drainage. A soil pH of 6.5 to 7.0 is ideal.
How deep should I plant asparagus crowns?
Asparagus crowns should be planted 6-8 inches deep in trenches. This depth allows for proper root development and protection from extreme temperatures.
Can I grow asparagus in containers?
Yes, asparagus can be grown in containers, but it requires a large pot (at least 18 inches in diameter) and well-draining potting mix. Container-grown asparagus may not be as productive as in-ground plants.
How often should I water asparagus?
Asparagus needs consistent moisture, especially during the growing season. Water deeply whenever the top inch of soil feels dry. Avoid overwatering, which can lead to root rot.
When is the best time to fertilize asparagus?
Fertilize asparagus in early spring before the spears emerge and again after the harvest season. Use a balanced fertilizer or a side dressing of compost.
How do I control asparagus beetles?
Asparagus beetles can be controlled by handpicking them off the plants. You can also use insecticidal soap or other organic insecticides.
What causes asparagus ferns to turn yellow?
Yellowing asparagus ferns can be caused by a variety of factors, including poor drainage, nutrient deficiencies, pests, or diseases. Inspect the plants carefully to identify the underlying cause.
Can I grow asparagus from seed?
Yes, you can grow asparagus from seed, but it takes longer to establish a producing plant. It is generally easier and faster to plant crowns.
How do I store harvested asparagus?
Stand the asparagus spears upright in a jar with a few inches of water. Cover the jar with a plastic bag and store it in the refrigerator. This will help keep the asparagus fresh and crisp for several days. Alternatively, wrap unwashed asparagus in damp paper towels and place in a plastic bag, squeezing out excess air.
How can I tell if my asparagus plant is male or female?
The easiest way to determine the sex of an asparagus plant is by looking at the berries. Female asparagus plants will produce small red berries, while male plants will not. All-male hybrids are preferred because they produce more spears and do not spread aggressively through seed.
What do I do with my asparagus bed in the winter?
In the fall, after the ferns have turned brown, cut them down to the ground level. Mulch the bed with straw or other organic material to protect the crowns from winter cold. A layer of compost can also be added to replenish nutrients in the soil.