The Ultimate Guide to Growing Asparagus: Your Questions Answered

Why Should I Grow Asparagus?

Imagine stepping into your backyard and harvesting tender, flavorful asparagus spears that put store-bought varieties to shame. As one of the few perennial vegetables, asparagus offers gardeners a chance to enjoy bountiful harvests for up to 20 years from a single planting. From the crisp springs of Maine to the sunny coasts of California, and even in frost-free Hawaii, asparagus can thrive in nearly every corner of the U.S. Whether you're a seasoned gardener or a curious beginner, this guide will walk you through every step of growing your own asparagus paradise – from selecting the perfect location to preserving your prized harvest.

Where Should I Plant My Asparagus?

When you're choosing the location for your asparagus bed, give it some careful thought. Because it's a perennial, your asparagus bed will most likely be around for at least 15 years (yes, you read that right!) So, take a walk around your property at different times of the day, noting the sunny and shaded areas.

• How Much Sun Does Asparagus Need? The recommended amount of sunlight to grow asparagus is 7 to 8 hours a day. Morning sunlight will be essential, and 6 hours of full sunlight should be considered the minimum. If you live in an area of the country that has sweltering hot summers, like Arizona, you may want to plan to plant where your asparagus plants are at least partially shaded in the late afternoon, either from a structure, a tree, or other landscaping feature. You can also install a shade cloth during the hottest part of the day, being sure to remove it each evening so that your asparagus can reap the benefits of the morning and early afternoon sunlight. It is also a good idea to look at the surrounding vegetation and landscaping. If you have young trees on your property, consider how tall and wide those trees will be 15 years from now. Shrubs, bushes, and even other vegetables, such as corn and tomatoes, can block the life-giving sun from your asparagus plants; if not now, then possibly in the future. If your options are limited due to space or sunlight requirements, consider planting your asparagus as a border plant. It's an attractive addition to any space, as you only harvest the choicest spears. This allows the remainder to mature and develop that ferny headpiece that is critical to energizing the crowns for next year's harvest. This fernlike decoration is quite beautiful, turning golden in the fall, and can be the perfect airy-looking border for taller annuals or perennials.
• What's the Ideal Soil pH for Asparagus? The next order of business is to check the pH level of your soil. Asparagus plants prefer a soil pH right around 6.5 to 6.8. You can fudge a little on each side of those numbers, however, if your soil is too alkaline or too acidic, your asparagus plants will not grow as well. An inexpensive soil testing kit can determine the pH quickly, or you can take a soil sample to your local University Cooperative Extension office for testing.

How Do I Prepare My Asparagus Bed?

Now that you've chosen where to plant your asparagus plants, it's time to prepare the bed. Many gardeners will do this in the fall; they prep, adjust the pH, and feed the bed in preparation for spring planting. However, you can be just as successful by doing a really good job prepping your asparagus bed in the spring. We do, however, recommend that you prepare the bed before your asparagus crowns arrive. Crowns are freshly harvested, which means the quicker they are in the ground after you receive them, the better.

If you are starting from scratch, you will have to till the area that you will be planting. The cleaner the bed starts, the less weeding and maintenance later. You will also want to discard any rocks and then till the soil to at least 12 inches deep. Tilling with several passes should break up any large clumps, ensuring adequate aeration throughout the soil for your new asparagus plants. A well-prepared bed will enable the roots of your asparagus plants to reach deep and establish well.

The final step, right before planting, is to dig a trench in which to plant your asparagus crowns. Make it 6 to 8 inches deep. If you have more than one row, the recommended distance between rows is 4 feet. If pinched for space, 3 feet will work, but never plant the rows less than 3 feet apart. This leaves you room to walk between the rows for harvesting, weeding, and checking the overall health of your asparagus plants. It also allows adequate air circulation to dry the ferns after it rains. If you're short on space, leave at least 8 inches between each plant, though for the best results you should plant the crowns 12 inches apart.

How Often Should I Water My Asparagus?

After the crowns are established, which usually takes 3-4 months, they will not need any additional watering (unless you live in a very hot and dry area).

After planting, and for the next 3 months, you will want to make sure they get a good soaking at least once per week. After that time frame, they should not need additional waterings unless you live in a very hot and dry area, if so, continue the weekly waterings.

What Kind of Asparagus Crowns Should I Choose?

Most gardeners prefer to grow asparagus from crowns rather than seeds. Growing from seed results in both male and female plants, but female plants tend to produce fewer desirable spears and can overcrowd the asparagus bed with seeds, reducing air circulation and increasing the risk of disease. Male plants, on the other hand, produce more flavorful, stout spears and do not produce seeds, making them the better choice. By purchasing guaranteed male asparagus crowns, you avoid the extra work of thinning and managing seedlings. Therefore, we recommend buying male asparagus crowns.

Should I Soak My Asparagus Crowns Before Planting?

Yes, soaking your asparagus crowns for 15 to 20 minutes before planting helps hydrate the roots and jump-starts their growth. Plant the crowns in a trench, spacing them 8 to 12 inches apart, and cover them with 1 to 2 inches of soil. Water generously and continue filling the trench as the shoots emerge until it is completely filled.

Which Asparagus Varieties Are Best for My Garden?

Consider factors like climate adaptability, disease resistance, and flavor when choosing asparagus varieties. Here are some popular options:

• Male Hybrid Varieties:

  • Jersey Knight: Highly productive and disease-resistant.
  • Jersey Giant: Large spears with excellent flavor.
  • Grande F1: High yeilding, designed for warm to hot climates.
  • UC157: Ideal for warmer climates.

• All-Male Varieties:

  • Millennium: Cold-hardy with high yield potential.
  • Guelph Eclipse: Uniform spears and disease resistance.

• Purple Varieties:

  • Purple Passion: Sweet flavor, turns green when cooked.

• Heritage Varieties:

  • Mary Washington: Open-pollinated with disease resistance but lower yield.

Planting a mix of varieties can extend your harvest season and offer different flavor profiles.

How Do I Care for My Asparagus Throughout the Seasons?

When you're planting your asparagus crowns for the first time, we recommend that you sprinkle Hi-Yield Triple Super Phosphate in the trench right before planting. With an NPK value of 0-45-0, this soil amendment is pure phosphorous. Due to the way asparagus grows and its perennial nature, you do not want to feed it with nitrogen. Nitrogen tends to spur quick plant growth; when it comes to asparagus, slow, strong, healthy growth is best. Phosphorous, on the other hand, enables the transfer of energy throughout the entire plant, encouraging the healthiest root growth. Phosphorous is also essential to the process of photosynthesis. Your asparagus plants use the most phosphorous when the spears are first forming, and then again when they flower. So, another moderate application of phosphorous is prudent when the harvest is complete and the ferny tops are appearing.

What Should I Do with My Asparagus in the Fall?

The next time you will want to pay particular attention to your asparagus bed's nutritional requirements is in the fall. Some gardeners choose to leave the ferny tops throughout the winter and cut them back in the spring. We recommend cutting your asparagus plants back to the ground right after the first frost. The reason for this is that fungus can grow, even in the winter, when the ferny tops don't get a chance to dry out. If you know you've got fungus on those tops, don't compost them. The fungus can over-winter and grow on anything you use that compost on in the spring.

Once you've cut them back, cover the whole bed with 1 to 2 inches of well-composted manure or compost. Then sprinkle with Triple Phosphate or Bone Meal, which will leach down to the roots. It'll provide that springtime pick-me-up as the soil warms and the spears start to grow again. This layer of compost will not only feed the plants but will help to insulate them from the harshest winter weather.

In the spring, the spears will grow right through that healthy layer. This even holds true in places that don't experience frost, like Hawaii, the exception being that once the ferny tops have been in place for about 4 months, you will want to cut the asparagus plants back to the ground. Then treat them the same as if they were growing where winter occurs.

What Are the Common Pests That Attack Asparagus?

1. Asparagus Beetles
• Identification: Adult beetles are blue-black with cream spots; larvae are gray green.
• Damage: Chew on spears and ferns, causing scarring and defoliation.
• Control: Handpick beetles, use row covers, apply neem oil or pyrethrin-based insecticides.
2. Cutworms
• Identification: Grayish-brown caterpillars that curl into a C-shape when disturbed.
• Damage: Cut off young spears at ground level.
• Control: Use cardboard collars around plants, apply diatomaceous earth, or use Bacillus thuringiensis (Bt).
3. Asparagus Aphids
• Identification: Tiny, gray-green insects that cluster on plants.
• Damage: Suck plant sap, causing stunted growth and distorted ferns.
• Control: Spray with strong water jet, use insecticidal soap, or introduce ladybugs.

What Diseases Can Affect My Asparagus Plants?

1. Fusarium Crown and Root Rot
• Symptoms: Yellowing ferns, stunted growth, reddish-brown lesions on roots.
• Cause: Soil-borne fungus (Fusarium oxysporum f. sp. asparagi).
• Prevention/Control: Plant resistant varieties, improve drainage, avoid overwatering.
2. Asparagus Rust
• Symptoms: Orange-brown pustules on ferns and spears.
• Cause: Fungus (Puccinia asparagi).
• Prevention/Control: Plant resistant varieties, remove infected plants, apply fungicides.
3. Purple Spot
• Symptoms: Purple lesions on spears and ferns.
• Cause: Fungus (Stemphylium vesicarium).
• Prevention/Control: Improve air circulation, avoid overhead watering, apply fungicides.

Why Isn't My Asparagus Growing Well?

When and How Should I Harvest My Asparagus?

When you harvest, you should only harvest the spears that are more than 3/8 inch in diameter (about the size of your little finger). This allows the smaller spears to develop that ferny top, which will, in turn, provide energy back to the crown, resulting in larger diameter spears the following year.

How Long Should I Wait Before Harvesting New Asparagus Plants?

Limit your first two annual harvests to the first 2 to 3 weeks of growth. This allows the remaining asparagus crowns to continue to develop for the healthiest and longest living asparagus bed. From the third year on, you will most likely be harvesting every other day when the asparagus spears are between 4 and 8 inches tall, usually for a period of 6 to 8 weeks, depending upon your geographical location.

The weather will also determine your harvest. Asparagus is a cool weather crop and one of the first vegetables to be ready for harvest. Don't pick the asparagus spears if they are no longer tight at the top. Let those open to display the ferns that will perpetuate next year's harvest. Nothing goes to waste!

What's the Best Way to Pick Asparagus?

When it comes to picking, many people will snap the asparagus spears at ground level. We suggest investing in an asparagus knife and cutting the spears 1 to 2 inches below the top of the soil. The reason for this is two-fold. First, there is less chance that you will damage the plant by pulling as you snap the spear. And second, that layer of soil helps to protect the crown after the spear is gone. It is also much quicker and easier to harvest with an asparagus knife, resulting in a longer spear.

Additionally, do not believe the myth that larger asparagus spears are not as tender. What IS true is that as the spear grows both in height and in diameter, the part below ground and sometimes about an inch above the ground will get a little tougher. Use a paring knife to cut off the tough part, saving the tenderest part of the spear for consumption or preserving. Compost the tough bits or feed them as an occasional snack to the chickens!

What Are the Health Benefits of Eating Asparagus?

Asparagus is not only delicious but also packed with nutrients:

• Low in calories: About 20 calories per 100g serving
• High in fiber: Supports digestive health
• Rich in vitamins: Especially vitamins A, C, E, and K
• Good source of folate: Important for cell growth and DNA formation
• Contains antioxidants: Such as glutathione, which has anti-aging properties
• Natural diuretic: May help with bloating and water retention

Asparagus also contains small amounts of potassium, phosphorus, and zinc, contributing to overall health and well-being. The naturally occurring nutrients, antioxidants, and amino acids will aid optimal growth and health.

How Can I Preserve My Asparagus Harvest?

Can I Dry Asparagus?

Yes, you can dry asparagus in a food dehydrator or oven and then add your dried asparagus to soups and stews throughout the year. First, wash the spears thoroughly and halve the largest spears. Then steam them for 4 to 5 minutes or blanch in water for 3.5 to 4.5 minutes, gently patting them dry with a paper towel. Finally, dry for 4 to 6 hours in a dehydrator. Of course, the drying time will depend upon the initial moisture content of the asparagus tips and the type of dehydrator you're using.

A conventional oven can take twice as long, though a convection oven with the fan going should take about the same length of time as a dehydrator. You will want to use perforated trays and allow 3 inches of clearance between the top and/or the bottom of your oven. Cheesecloth stretched over your baking pans or over a metal frame is perfect to provide exceptional air circulation, while not reacting negatively with the asparagus spears. Set your oven thermostat at 140° to 150°F and prop the door open a little to allow moisture to escape. The asparagus tips are dry when they are leathery looking and brittle. Store serving-size portions in airtight containers or bags in a cool, dry place.

How Do I Pickle Asparagus?

This is one of the most popular ways to preserve asparagus! Due to its low acidity, asparagus requires a pressure canner for home-canning, but pickling will enable you to safely use a water bath canner.

What's the Best Way to Freeze Asparagus?

This is a simple way to keep asparagus as close to fresh as possible. Blanch small spears for no longer than two minutes and larger spears for not more than three. Allow the spears to dry, preferably in the refrigerator, spreading them out in a single layer on a baking sheet and patting with a paper towel as needed. Then place in freezer bags or containers, in serving-size portions, removing as much of the air as possible. If you vacuum seal, you can skip the blanching process. This keeps the texture fresh, while the spears remain that gorgeous, just-picked green.

Is It Safe to Can Asparagus at Home?

Yes, but this is the best long-term storage solution, though it will result in a softer texture. Asparagus has low acidity, so you'll need a pressure canner. You can either cut the spears to fit quart jars, or cut in smaller pieces, like green beans. You'll need approximately 16 pounds to fill 9 pints, or 24 pounds to fill quart jars. Be sure to use a spatula to squeeze the air bubbles out of the jars, after filling with boiling water and leaving 1-inch headspace, before applying the lids. Process at 10 lbs. of pressure for 25 minutes.

What Are Some Simple Asparagus Recipes I Can Try?

Lemon Garlic Roasted Asparagus

• Ingredients: 1 lb asparagus, 2 tbsp olive oil, 2 cloves minced garlic, 1 lemon, salt, pepper
• Instructions:
1. Preheat oven to 400°F (200°C)
2. Toss asparagus with olive oil, garlic, salt, and pepper
3. Roast for 10-15 minutes until tender-crisp
4. Squeeze lemon juice over before serving

Asparagus and Goat Cheese Frittata

• Ingredients: 8 eggs, 1/2 cup milk, 1 cup chopped asparagus, 4 oz crumbled goat cheese, salt, pepper
• Instructions:
1. Whisk eggs with milk, salt, and pepper
2. Pour into an oven-safe skillet with sautéed asparagus
3. Top with goat cheese and bake at 375°F (190°C) for 15-20 minutes until set

How Does Growing Asparagus Contribute to Sustainable Gardening?

Growing asparagus can contribute to sustainable gardening practices in several ways:

• Long-term crop: Reduces need for annual tilling and soil disturbance
• Perennial nature: Helps prevent soil erosion and improves soil structure over time
• Low water needs: Once established, asparagus is relatively drought-tolerant
• Minimal pesticide requirements: Especially when using companion planting and integrated pest management
• Carbon sequestration: Perennial root systems help store carbon in the soil
• Biodiversity: Asparagus ferns provide habitat for beneficial insects

Implement sustainable practices such as:

• Using organic mulch to suppress weeds and retain moisture
• Practicing crop rotation in the years before establishing an asparagus bed
• Utilizing rainwater harvesting for irrigation
• Composting asparagus waste to return nutrients to the soil

By growing asparagus sustainably, you not only enjoy fresh, homegrown produce but also contribute to a healthier environment and more resilient local ecosystem.

Are You Ready to Embrace Your Asparagus Adventure?

Congratulations! You've now embarked on a journey through the fascinating world of asparagus cultivation. From selecting the perfect sunny spot in your garden to savoring your homegrown spears in a delicious frittata, you're well-equipped to become an asparagus aficionado.

Remember, growing asparagus is a long-term commitment that rewards patience and care with bountiful harvests for years to come. Here are some key takeaways to keep in mind:

1. Choose your planting location wisely, considering sun exposure and soil quality.
2. Invest time in preparing your asparagus bed properly – it'll pay off in the long run.
3. Select high-quality, preferably male, asparagus crowns for optimal yield.
4. Practice sustainable gardening techniques to benefit both your asparagus and the environment.
5. Be patient during the first couple of years as your asparagus establishes itself.
6. Harvest responsibly to ensure continued production for up to 20 years.
7. Explore various preservation methods to enjoy your asparagus year-round.

As you watch your asparagus ferns sway in the breeze and anticipate each spring's tender spears, take pride in knowing you're participating in a gardening tradition that spans generations. Your asparagus patch is more than just a source of delicious vegetables – it's a testament to your dedication as a gardener and a contribution to a more sustainable food system.

So, roll up your sleeves, get your hands dirty, and let the asparagus adventure begin. Happy gardening, and may your harvests be plentiful!