Asparagus is a delicious and nutritious vegetable that adds a touch of elegance to any meal. It is rich in fiber, vitamin C, folate, and antioxidants. Growing your own asparagus is not only rewarding but also surprisingly easy, even for beginner gardeners. This guide will provide you with all the information you need to know about growing asparagus, from planting to harvesting.
Table of Contents
What You Need To Know
Asparagus is a perennial plant that can produce edible spears for up to 20 years. Unlike most vegetables, asparagus does not need to be replanted every year. Once established, it will grow back every spring with minimal care. Asparagus is also versatile in the kitchen, as it can be eaten raw, steamed, roasted, grilled, or sautéed.
Growing your own asparagus is easier than you might think. All you need is a sunny spot, well-drained soil, and some patience. Asparagus takes two years to produce its first harvest, but once it does, you will be rewarded with fresh, tender, and flavorful spears every year.
Preparing to Plant
Choosing a Planting Site:
The first step to growing asparagus is choosing a suitable planting site. Asparagus prefers full sun, but it will tolerate some shade. However, too much shade will reduce the yield and quality of the spears. Choose a location that receives at least six hours of direct sunlight per day.
Asparagus also needs well-drained soil with a pH between 6.5 and 7.0. Asparagus does not like wet or acidic soil, as it can cause root rot and fungal diseases. You can test your soil pH with a kit from a garden center or online. If your soil is too acidic, you can raise the pH by adding lime. If your soil is too alkaline, you can lower the pH by adding sulfur.
Another factor to consider when choosing a planting site is the longevity of asparagus. Asparagus is a long-term crop that can last for decades. Therefore, you should choose a location that is undisturbed and can support asparagus for many years. Avoid planting asparagus near trees, shrubs, or other plants that might compete for space, water, or nutrients.
Preparing the Soil:
Once you have chosen a planting site, you need to prepare the soil for asparagus. The best time to do this is in the fall or early spring before planting. Start by clearing the area of any weeds, rocks, or debris. Then, loosen the soil to a depth of 12 inches with a shovel or a tiller. This will improve the drainage and aeration of the soil, which are essential for asparagus.
Next, enrich the soil with organic matter, such as compost or manure. Asparagus is a heavy feeder that requires a lot of nutrients to grow well. Adding organic matter will increase the fertility and water-holding capacity of the soil. You can also add some balanced fertilizer, such as 10-10-10, to give the asparagus a boost. Mix the organic matter and fertilizer into the top 6 inches of the soil.
Choosing Crowns or Seeds:
There are two ways to grow asparagus: from crowns or from seeds. Crowns are the dormant roots of one-year-old asparagus plants. They are the easiest way to grow asparagus, offering quicker results than seeds. You can buy crowns from nurseries, garden centers, or online. Look for healthy and disease-free crowns with thick and firm roots.
Seeds are a more affordable option but require more patience and care. You can buy seeds from seed catalogs or online. Look for seeds that are fresh and viable. You can start seeds indoors in pots or trays, or sow them directly in the prepared soil in early spring. However, seeds take longer to germinate and grow than crowns, and they may not produce uniform plants.
Grow Asparagus From Crowns:
The best time to plant crowns is in early spring, as soon as the soil is workable. To plant crowns, dig trenches 6-8 inches deep and 12-18 inches apart. Place crowns in the trenches with the roots spread out. Cover the crowns with 2 inches of soil and water well. Gradually backfill the trenches with soil as the asparagus grows, leaving the tips exposed. By the end of the season, the soil should be level with the ground.
Grow Asparagus From Seeds:
If you choose to grow asparagus from seeds, you can sow them directly in the prepared soil in early spring, after the last frost. Sow seeds 1/2 inch deep and 2 inches apart. Thin seedlings to 12-18 inches apart when they are 4-6 inches tall. Protect young seedlings from frost with mulch or row covers. Alternatively, you can start seeds indoors in pots or trays 8-10 weeks before the last frost. Transplant seedlings to the garden when they are 12-14 inches tall.
Care and Maintenance
Asparagus needs regular watering, especially during dry periods. Aim to keep the soil consistently moist but not soggy. Water deeply and infrequently, rather than shallowly and frequently. A good rule of thumb is to water asparagus once a week, providing 1-2 inches of water per week. You can use a rain gauge or a finger to check the soil moisture. Avoid overhead watering, as it can promote fungal diseases.
Asparagus is a heavy feeder that benefits from regular fertilization. Apply a balanced fertilizer, such as 10-10-10, in early spring and again in mid-summer. Follow the label instructions for the amount and frequency of application. Alternatively, you can use organic fertilizers, such as compost, manure, or fish emulsion. Avoid using high-nitrogen fertilizers, as they can encourage leafy growth at the expense of spears.
Asparagus does not like to compete with weeds for resources. Therefore, it is important to keep the asparagus bed weed-free. Hand-pull or hoe weeds as soon as they appear. Do not use herbicides, as they can harm the asparagus plants. You can also mulch around the asparagus plants with organic materials, such as straw, grass clippings, or wood chips. Mulch will help retain moisture, suppress weeds, and moderate soil temperature.
Disease and Pest Control:
Asparagus is generally a low-maintenance crop, but it can be affected by some diseases and pests. Some of the common asparagus diseases are asparagus rust, fusarium wilt, and crown rot. These diseases can cause yellowing, wilting, and dying of the asparagus plants. To prevent and control these diseases, choose resistant varieties, plant in well-drained soil, rotate crops, and remove and destroy infected plants.
Some of the common asparagus pests are asparagus beetle, cutworm, and aphid. These pests can damage the asparagus spears and foliage by feeding, chewing, or sucking on them. To prevent and control these pests, monitor the plants regularly, hand-pick or knock off the pests, and use organic control methods, such as insecticidal soap, neem oil, or diatomaceous earth.
You can also geow asparagus companion plants at the same asparagus planting site that helps repel pests that cause damage to your plants.
When to Harvest:
One of the most challenging aspects of growing asparagus is knowing when to harvest. Asparagus takes two years to produce its first harvest, as it needs time to establish a strong root system. If you harvest too soon or too much, you will weaken the plants and reduce the future yield.
The general rule is to wait until the second year after planting to harvest asparagus. In the second year, you can harvest a few spears for a short period of time, about two weeks. In the third year and beyond, you can harvest more spears for a longer period of time, about six to eight weeks.
Harvest spears when they are 6-8 inches tall, before the tips start to open. The spears will grow quickly in warm weather, so check the plants daily and harvest as needed. Cut spears with a sharp knife at the base of the plant, just below the soil surface. Be careful not to damage the emerging spears or the crown.
To ensure a healthy and productive asparagus bed, follow these harvesting techniques:
- Harvest only a few spears each day to avoid stressing the plants.
- Harvest the thickest spears first, as they are the most tender and flavorful.
- Leave some spears to grow into ferns, as they will provide energy and nutrients to the plants for the next year.
- Stop harvesting by mid-summer to allow the plants to store energy for the following year.
- Cut back the ferns to the ground in late fall or early winter, after they turn yellow or brown.
Tips for Success
Here are some additional tips to help you grow asparagus successfully:
- Choose asparagus varieties that are well-suited to your climate. Some popular varieties are Jersey Knight, Jersey Giant, Purple Passion, and Mary Washington.
- Mulch around the asparagus plants to help retain moisture and suppress weeds. You can also add some salt to the mulch, as asparagus is tolerant of salt and it can deter some weeds and pests.
- Divide and replant asparagus beds every 7-10 years. This will rejuvenate the plants and increase the yield. To divide asparagus, dig up the crowns in early spring and cut them into smaller pieces, each with several roots and buds. Replant the divisions in a new bed with fresh soil and compost.
Growing your own asparagus is a rewarding experience that provides you with fresh, delicious vegetables for years to come. By following the tips in this guide, you can be sure to enjoy a bountiful harvest of asparagus.
FAQs on Growing Asparagus:
What is the best time to plant asparagus?
Asparagus is typically planted in the spring, after the last frost, when the soil temperature has reached at least 60°F.
Do I need to plant asparagus crowns or seeds?
Planting crowns is easier and faster for beginners as they will produce spears in the second year. Seeds take longer to mature and require more patience.
How much sunlight and space does asparagus need?
Asparagus requires at least 6 hours of direct sunlight per day. Plants can grow up to 6 feet tall and 3 feet wide, so ensure ample spacing between them.
How often do I need to water and fertilize asparagus?
Aim for deep watering once a week, especially during hot, dry weather. Apply a balanced fertilizer every 4-6 weeks throughout the growing season.
When can I start harvesting asparagus spears?
Avoid harvesting in the first year. You can harvest a few spears in the second year and for 6-8 weeks in the third year and beyond. Cut spears just below the soil line using a sharp knife.
How do I control pests and diseases in my asparagus patch?
While relatively resistant, asparagus can be susceptible to aphids, beetles, and rust. Use organic methods like insecticidal soap or neem oil whenever possible.
How long will my asparagus plants produce spears?
With proper care, well-established asparagus plants can continue producing delicious spears for up to 20 years.
Can I extend my asparagus harvest season?
Yes, planting different varieties with varying maturity dates allows you to enjoy fresh asparagus for longer.