Asparagus is a perennial vegetable that greets gardeners each spring with its tender spears. Known for its ferny foliage, it can also serve as an ornamental plant. Varieties like 'Mary Washington' and 'Purple Passion' offer unique traits, from productivity to color. Growing asparagus requires patience, as it takes 2-3 years to establish and demands specific care conditions.
- Common Names: Garden Asparagus, Asparagus Fern, Emerald Fern
- Scientific Name: Asparagus officinalis
- Plant Type: Perennial, vegetable
- Plant Height: 3-5 feet
- Growing Difficulty: Medium
- Growing Time: 2-3 years
- Bloom Time: Spring, Summer
- Temperature: Prefers 70-85°F during the day
- Hardiness Zone: 3-10 (Find your hardiness zone here)
- Sunlight: Full Sun
- Soil pH: 6.5-7.0
- Watering Frequency: 1-2 inches per week
- Plant Spacing: 12-18 inches apart
Different Methods to Grow Asparagus
Planting from Crowns
This method involves planting the roots of asparagus plants, known as crowns, in early spring. Crowns are typically sold as bare roots and should be firm and fresh.
- Pros: Faster time to harvest compared to seeds.
- Cons: Initial cost may be higher than seeds.
Growing from Seeds
Seeds are started indoors in late winter under a heat lamp. They are soaked overnight before planting half an inch deep in a seed starting tray.
- Pros: More variety in types of asparagus.
- Cons: Takes longer to reach harvest (2-3 years).
"Little-by-Little" Method
This method involves gradually filling the trench with soil as the asparagus spears grow, adding 2 inches of soil each time the spears reach 2-3 inches tall.
- Pros: Thought to result in stronger plants overall.
- Cons: More labor-intensive as it requires multiple additions of soil throughout the season.
Ideal Soil and Location Requirements
Asparagus thrives in sandy, loamy soil rich in organic matter, with a pH of 6.5-7.0. Ensure the soil is well-drained and loosened to a depth of 12-15 inches. Choose a sunny location, ideally with 6-8 hours of direct sunlight daily.
When to Plant Asparagus
Plant asparagus in early spring as soon as the soil can be worked. Start seeds indoors about four weeks before the last expected frost and transplant seedlings just after the last frost. This timing ensures optimal growth and establishment before the growing season begins.
Growing Asparagus Outdoors
The best method to grow asparagus outdoors is by planting crowns in a trench. This method is the easiest because it avoids the several years of waiting required when starting from seeds. Here’s a step-by-step guide for home gardeners:
- Choose a sunny site. Ensure the location gets 6-8 hours of direct sunlight daily and has well-drained soil.
- Prepare the soil. Work in a 2- to 4-inch layer of compost or aged manure. Loosen the soil to a depth of 12-15 inches.
- Dig the trench. Make a trench 12-18 inches wide and 6-8 inches deep.
- Soak the crowns. Briefly soak the asparagus crowns in lukewarm water before planting.
- Create soil mounds. Form 2-inch-high ridges of soil along the center of the trench.
- Place the crowns. Set the crowns on top of the ridges, spacing them 12-18 inches apart.
- Cover with soil. Fill the trench with soil and compost all at once, covering the crowns completely.
- Water well. Water the newly planted crowns thoroughly to help them settle in.
- Mulch the bed. Apply a 4- to 6-inch layer of mulch to retain moisture and control weeds.
- Maintain watering. Provide 1-2 inches of water per week during the first two growing seasons.
- Fertilize annually. Top dress with compost in early spring or fall and apply an organic fertilizer in mid-spring.
Growing Asparagus Indoors
Growing asparagus indoors is not typically recommended due to its extensive root system and long growing period. However, it is possible to grow asparagus in containers indoors with proper care and attention. Here’s a step-by-step guide for home gardeners:
- Choose a large container. Use a container that is at least 18 inches deep and 24 inches wide to accommodate the root system.
- Ensure good drainage. Make sure the container has drainage holes to prevent waterlogging.
- Fill with quality soil. Use a sandy, loamy soil mix with a pH of 6.5-7.0, enriched with organic matter.
- Plant crowns. Soak asparagus crowns in lukewarm water for 30 minutes before planting.
- Place crowns. Set the crowns 12-18 inches apart in the container, with the roots spread out and the buds facing up.
- Cover with soil. Cover the crowns with 2 inches of soil initially, then gradually add more soil as the spears grow until the container is filled.
- Provide adequate light. Place the container in a location that receives 6-8 hours of direct sunlight daily or use a grow light.
- Water regularly. Keep the soil consistently moist but not waterlogged, providing 1-2 inches of water per week.
- Fertilize. Apply an organic fertilizer in mid-spring and top dress with compost annually.
- Mulch. Add a 4-6 inch layer of mulch to retain moisture and control weeds.
- Wait to harvest. Do not harvest spears in the first two years to allow the plants to establish.
Asparagus is a perennial plant that can be productive for 15, 20, and sometimes up to 30 years once established.
Caring for Asparagus
- Watering: Asparagus plants need consistent moisture, especially during the first two growing seasons. Aim to provide 1-2 inches of water per week. For mature plants, about 1 inch per week should suffice.
- Fertilizing: Use an organic fertilizer during the growing season. In the second year, side-dress with compost in spring and early fall. After harvesting, top-dress with a balanced organic fertilizer or another inch of rich, weed-free compost.
- Pest Management: Common pests include asparagus beetles and cutworms. Handpick beetles and drop them in soapy water. For cutworms, clear away weeds and other plant matter. Neem oil can also help control beetles.
- Harvesting: Skip harvesting in the first two years to allow the plants to establish. In the third year, harvest spears sparingly. Established plants can be harvested for up to 8 weeks, cutting spears when they are 8-10 inches tall and 1/2 to 3/4 inch thick.
- Mulching and Weeding: Keep the asparagus bed thickly mulched to retain moisture and control weeds. Hand-pull weeds, especially during the first two years, to avoid disturbing the shallow roots.
Common Challenges With Asparagus
Asparagus is a relatively easy plant to grow once it gets established, but it does require some patience. It takes about 2-3 years before you can start harvesting, which can be a test of endurance for new gardeners. However, once it starts producing, asparagus can be a rewarding perennial that comes back year after year. In my experience, the initial wait is well worth it, as the plant can be productive for up to 30 years with proper care.
Despite its resilience, growing asparagus does come with its challenges. One of the most common issues is managing weeds, especially in the first two years when the plants are still establishing. Proper drainage is crucial to prevent root rot, and pests like asparagus beetles can be a persistent problem. Diseases such as rust and Fusarium wilt can also affect the plants, making it essential to choose disease-resistant varieties and maintain good garden hygiene. But with a bit of diligence, these challenges can be managed, allowing you to enjoy fresh asparagus for many years.
Safety of Asparagus for Pets
Asparagus is generally safe for cats, dogs, and other pets. However, the red berries produced by female asparagus plants are toxic. If you suspect your pet has ingested these berries, contact the ASPCA's 24-hour hotline for assistance.
Frequently Asked Questions
How long does it take for asparagus to grow?
Asparagus typically takes 2-3 years to establish before you can start harvesting. Once established, it can be productive for up to 30 years, providing a reliable annual harvest each spring.
Can asparagus be grown in containers?
Yes, asparagus can be grown in containers, but it requires a large, deep container to accommodate its extensive root system. Ensure the container has good drainage and is filled with a sandy, loamy soil mix.
How much asparagus do you get from one plant?
From one mature asparagus plant, you can expect to harvest about 10-15 spears annually. This yield can continue for many years with proper care and maintenance.
What are the best companion plants to grow with asparagus?
Some of the best companion plants for asparagus include basil, parsley, dill, nasturtium, eggplants, tomatoes, and spinach. These plants can help deter pests and improve soil health.
