How To Plant And Grow Asparagus – For 20 Years Of Gourmet Harvests
To successfully grow asparagus, choose a sunny spot with well-drained soil and a pH between 6.5 and 7.0. Plant one-year-old crowns in trenches 6 to 8 inches deep during early spring.
The secret to a long-lasting bed is patience; avoid harvesting any spears for the first two years to allow the root system to establish. With proper mulching and weeding, your asparagus patch can produce tender spears for over two decades.
Establishing a permanent vegetable patch is one of the most rewarding projects for any home gardener. We all want a garden that provides a high return on investment with minimal replanting each season.
This guide will show you exactly how to establish a “legacy” asparagus bed that yields tender, flavorful spears for up to 20 years. I will walk you through the essential steps of soil preparation, variety selection, and the critical maintenance required for long-term success.
We will cover everything from the initial trenching techniques to managing common pests like the asparagus beetle. By the end of this article, you will have a clear roadmap for how to plant and grow asparagus in your own backyard.
Choosing the Best Asparagus Varieties
Before you pick up a shovel, you must decide which variety fits your climate and culinary preferences. Asparagus plants are dioecious, meaning individual plants are either male or female.
Male plants are generally preferred by modern gardeners because they do not spend energy producing seeds. This allows the plant to put all its resources into growing thicker, more robust spears.
The “Jersey” series, including Jersey Knight and Jersey Giant, are popular all-male hybrids. They offer excellent disease resistance and high yields in a variety of soil types.
If you prefer heirloom varieties, Mary Washington is a classic choice that produces reliable crops. However, be prepared to weed out “volunteer” seedlings that sprout from the female plants’ red berries.
For something unique, consider Purple Passion. These spears are sweeter and more tender than green varieties, though they turn green when cooked.
How to Plant and Grow Asparagus: Site Selection and Soil Prep
Asparagus is a long-term resident of your garden, so choosing the right location is non-negotiable. Select a spot that receives at least 6 to 8 hours of full sun daily.
Avoid areas where water pools after a heavy rain, as soggy soil leads to crown rot. Asparagus roots can reach 10 feet deep, so they need a space where they won’t be disturbed by future construction.
Start by testing your soil pH; these plants thrive in slightly acidic to neutral soil (6.5 to 7.0). If your soil is too acidic, incorporate lime several months before planting to raise the pH level.
Heavy clay soils benefit significantly from the addition of aged compost or well-rotted manure. This organic matter improves drainage and provides the slow-release nutrients these heavy feeders require.
Remove all perennial weeds from the site before you begin, as they are difficult to manage once the asparagus is established. Use a sturdy garden fork to loosen the soil to a depth of 12 inches.
The Importance of Drainage
If your yard has poor drainage, consider building a raised bed for your asparagus. This ensures the crowns stay above the water table during wet spring months.
Construct the bed at least 12 inches high using rot-resistant wood or stone. Fill it with a mix of topsoil, compost, and coarse sand to create the ideal growing medium.
The Step-by-Step Planting Process
Most gardeners start with one-year-old crowns rather than seeds to save time. Crowns look like a mass of yellowish-brown roots and should be planted in early spring as soon as the soil can be worked.
- Dig the Trench: Create a trench 12 inches wide and 8 inches deep. If planting multiple rows, space the trenches 3 feet apart.
- Create Mounds: Inside the trench, create small mounds of soil spaced 12 to 18 inches apart. These mounds help the roots spread out naturally.
- Position the Crowns: Place a crown on top of each mound, draping the roots down the sides like an octopus. Ensure the “bud” or growing point is facing upward.
- Initial Covering: Cover the crowns with only 2 inches of soil. Do not fill the entire trench at once, as this can smother the young shoots.
- Gradual Filling: As the spears begin to grow, gradually add more soil to the trench over the next few weeks. Continue until the trench is level with the surrounding ground.
Always wear durable gardening gloves when handling crowns to protect your hands from abrasions. Use a sharp spade to ensure clean edges on your trenches, which helps with water retention.
Essential Care and Maintenance
Once your bed is established, consistency is the key to longevity. Knowing how to plant and grow asparagus is only half the battle; you must also master the art of maintenance.
Water is critical during the first two years of growth. Provide at least 1 inch of water per week, ensuring the moisture reaches the deep root system without saturating the surface.
Apply a balanced 10-10-10 NPK fertilizer in early spring before the spears emerge. This provides the nitrogen needed for foliage growth and the phosphorus and potassium required for root health.
Mulching is your best defense against weeds and moisture loss. Apply a 3-inch layer of straw, shredded leaves, or wood chips around the plants once the soil has warmed up.
Avoid using salt to kill weeds, a common “old wives’ tale” in gardening. While asparagus is somewhat salt-tolerant, excess salt eventually ruins the soil structure and harms beneficial soil microbes.
Managing the Fern Stage
After the harvest season ends, the spears will grow into tall, feathery “ferns.” Do not cut these down during the summer, as they are essential for photosynthesis.
The ferns collect energy and store it in the crowns for next year’s crop. Only cut the ferns back to the ground after they have turned completely brown in late autumn or winter.
Pest and Disease Troubleshooting
The most common visitor to your patch will be the asparagus beetle. These small, blue-black beetles with yellow spots chew on the spears and foliage, weakening the plant.
Check your plants regularly in the morning and hand-pick any beetles you find. Drop them into a bucket of soapy water to dispose of them safely without using harsh chemicals.
Asparagus rust is a fungal disease that appears as orange or reddish-brown spots on the ferns. To prevent this, ensure there is adequate air circulation by following proper spacing guidelines.
If you live in a humid climate, look for disease-resistant varieties like the Jersey series. Always clean your garden tools with a 10% bleach solution after working with infected plants to prevent spreading spores.
Fusarium wilt is another concern, often causing the plants to yellow and stunt. Maintaining a neutral soil pH and avoiding overwatering are the best preventative measures for this soil-borne pathogen.
The Art of the Harvest
The hardest part of learning how to plant and grow asparagus is waiting to eat it. You must resist the urge to harvest any spears during the first year of planting.
In the second year, you may harvest lightly for about two weeks. By the third year, the root system is usually strong enough for a full harvest season of 6 to 8 weeks.
Harvest spears when they are 6 to 10 inches tall and about the thickness of a pencil. The tips should be tight and firm; if they start to “feather out,” the spear will be tough and woody.
Use a sharp harvest knife or garden shears to cut the spears at or just below the soil surface. Be careful not to damage the emerging buds of nearby spears that are still underground.
Once the weather turns hot and the spears become thin (less than the diameter of a pencil), stop harvesting. This allows the plant to enter its fern stage and recharge for the following year.
Safe Tool Handling and Storage
Maintaining your tools is just as important as maintaining your plants. A dull knife will tear the asparagus tissue, creating an entry point for fungal pathogens.
Sharpen your harvest knife annually using a whetstone. Always store your tools in a dry place to prevent rust, and wipe them down with a light coat of oil after each use.
When applying fertilizers or organic amendments, wear a dust mask if the material is dry and powdery. This prevents inhalation of particles that can irritate your respiratory system.
If you use any organic pesticides, such as neem oil, apply them in the late evening. This protects beneficial pollinators like bees that are active during the day.
Frequently Asked Questions
Can I Grow Asparagus From Seeds Instead of Crowns?
Yes, you can grow asparagus from seeds, but it adds an extra year to the process. You will need to start seeds indoors 10-12 weeks before the last frost and transplant them carefully.
How Many Asparagus Plants Do I Need for a Family of Four?
For a consistent supply, plan on 10 to 15 plants per person. This means a family of four would need a bed containing approximately 40 to 60 plants.
Why Are My Asparagus Spears So Thin?
Thin spears are often a sign of an aging bed, overcrowding, or lack of nutrients. Ensure you are fertilizing annually and that the plants aren’t competing with heavy weed growth.
Do I Need to Salt My Asparagus Bed?
No, you should not use salt. While it was once used for weed control, it can damage the soil’s long-term health and is not necessary for the growth of the asparagus itself.
Can You Plant and Grow Asparagus in Containers?
It is possible but difficult due to the plant’s massive root system. If you try, use a very large, deep container (at least 20 gallons) and ensure it has excellent drainage.
Conclusion
Learning how to plant and grow asparagus is an investment in your garden’s future. By choosing the right variety, preparing the soil with care, and practicing patience during the early years, you create a sustainable source of gourmet food.
Remember that the key to a thriving patch lies in the “fern stage”—letting the plant grow tall and green after the harvest. This simple act of restraint ensures the crowns remain healthy and productive for decades to come.
Now is the perfect time to start planning your bed. Order your crowns early, test your soil, and get ready to enjoy the unmatched flavor of home-grown asparagus next spring!
Taylor pairs an engineer's eye with years of hands-on work in soil, lawns and outdoor machinery. He tests ideas in his own garden, keeps tractors and mowers running himself, and speaks to local horticulture groups. Every Garden Aider guide is written to be practical, accurate and safe to follow.
“To bring life alive, you just need to mix some love with the compost, bedding, and gardening machines.”