Asparagus in Zone 7A — Midwest

Asparagus is a true sign of spring in the Midwest, and the flavor of fresh-picked spears is unbeatable. Growing your own means you get to enjoy this delicacy straight from the garden, not to mention the satisfaction of harvesting something you nurtured for years. Plus, asparagus is a perennial, so it will come back year after year, making it a worthwhile investment for any Midwest gardener.

Our Midwest weather can be unpredictable, with cold winters and the occasional summer heat spell. But don't let that deter you. Asparagus is surprisingly hardy, and with a little planning, you can enjoy a bountiful harvest. With our 193-day growing season, you'll have plenty of time to get your asparagus established and thriving.

Transplant your asparagus crowns outdoors in early to mid April. Before planting, be sure to harden them off by gradually exposing them to outdoor conditions for about a week. This helps them adjust to the Midwest weather.

Plant the crowns 18-24 inches apart in well-drained soil. Remember, we often have a variable spring here, so watch for late frost warnings and be prepared to cover your newly planted crowns if needed. It's best to buy 1-year-old crowns from a local nursery, as growing from seed takes much longer to reach harvest.

Asparagus needs moderate watering, especially during its first two years as it gets established. Once established, its deep roots make it fairly drought-tolerant. However, don't neglect watering, especially during our summer heat spells.

Keep an eye on the soil moisture. Stick your finger about 2 inches deep into the soil; if it feels dry, it's time to water. Aim for about 1 inch of water per week, either from rainfall or irrigation. Given our moderate-to-humid summers, it's best to water at the base of the plants to avoid creating overly moist conditions that can lead to fungal diseases.

If the spears are thin and stunted, it could be a sign of underwatering. Yellowing or wilting ferns, on the other hand, can indicate overwatering. Adding a layer of mulch around the base of the plants helps retain moisture and suppress weeds, which is particularly helpful given our wet-summer rainfall.

Asparagus pruning is minimal, which is great for busy Midwest gardeners. During the growing season, let the ferns grow tall and lush. These ferns are essential for feeding the crown and ensuring a good harvest in future years.

Come late fall or early spring, after the ferns have turned brown and died back, you can cut them down to the ground. This helps keep the garden tidy and prevents any potential disease from overwintering. Remember, don't harvest asparagus for more than 8 weeks per season to avoid weakening the plant.

In Zone 7A of the Midwest, you can expect your first asparagus harvest in early April through early November, but remember it takes about two years from transplant. Look for spears that are 6-8 inches tall with tight, closed tips. These are the most tender and flavorful.

To harvest, snap the spears off at ground level. Be careful not to damage the surrounding spears or the crown. Continue harvesting regularly as new spears emerge to encourage continued production.

Once the spears start to become thin, about the width of a pencil, it's time to stop harvesting for the season and let the remaining spears fern out. As the first frost approaches in mid- October, let the plant focus on storing energy for next year's crop.

Asparagus can face a few challenges here in the Midwest. Here are some common problems and how to deal with them:

Asparagus Beetle *What it looks like:* Small, metallic blue-black beetles and their larvae munching on spears and ferns, leaving behind brown or yellow damage. *What causes it:* These beetles are attracted to asparagus plants and can quickly defoliate them if left unchecked. *How to fix/prevent it:* Handpick beetles and larvae, especially in spring. Encourage beneficial insects like ladybugs. Insecticidal soap can also be used, following label instructions.

Crown Rot from Poor Drainage *What it looks like:* Yellowing or wilting ferns, stunted growth, and mushy, rotting crowns. *What causes it:* Our clay soil, combined with wet-summer rainfall, can lead to poor drainage and create conditions favorable for crown rot. *How to fix/prevent it:* Ensure good drainage by planting asparagus in raised beds or amending the soil with plenty of organic matter. Avoid overwatering. Remove and destroy infected plants to prevent the spread of the disease.

Thin Spears from Over-Harvesting *What it looks like:* Spears that are noticeably thinner than usual, often appearing spindly and weak. *What causes it:* Harvesting for too long or too frequently depletes the plant's energy reserves, leading to thinner spears. *How to fix/prevent it:* Limit your harvest to no more than 8 weeks per season. Allow the remaining spears to fern out and replenish the plant's energy.

Midwest Specific Challenges: Our moderate-to-hot heat and moderate-to-humid humidity can create favorable conditions for pests and diseases. The wet-summer rainfall can exacerbate drainage issues, especially in clay soil. Regular monitoring and proactive measures, such as ensuring good drainage and controlling pests, are essential for growing healthy asparagus in the Midwest.

Companion planting can be a great way to help your asparagus thrive here in the Midwest. Tomatoes, parsley, and basil are all good companions for asparagus. Tomatoes help deter asparagus beetles, while parsley attracts beneficial insects that prey on asparagus pests. Basil can also help repel asparagus beetles and other unwanted insects.

Onions and garlic, on the other hand, are not good companions for asparagus. They can inhibit asparagus growth and should be avoided. By choosing the right companion plants, you can create a healthy and productive asparagus bed in your Midwest garden.