Asparagus in Zone 8B — Texas

Asparagus is a garden treasure worth the wait, even in our unpredictable Texas climate. The fresh, homegrown flavor is far superior to anything you'll find at the store, and it's incredibly versatile in the kitchen. Plus, there's a real satisfaction in harvesting those first spears after patiently tending to your plants.

Sure, growing asparagus in Texas comes with its challenges, like the extreme heat and occasional drought. But with a little planning and the right timing, you can enjoy a bountiful harvest from your asparagus patch. Our long 273-day growing season gives you a great head start.

Transplant your asparagus crowns outdoors in late February through early March. This gives them a chance to settle in before the real Texas heat kicks in. Before planting, be sure to harden off your asparagus crowns by gradually exposing them to outdoor conditions for about a week.

When transplanting, space the crowns about 18-24 inches apart. Remember, you're buying 1-year-old crowns, not starting from seed. It takes a few years to get a harvest, so be patient.

Keep an eye on the weather forecast around transplant time. We can still get some unpredictable freezes in late February and early March, so be prepared to cover your newly planted crowns if necessary.

Asparagus needs moderate watering, especially when it's getting established. Once they're a couple of years old, those deep roots make them pretty drought-tolerant. But don't let them dry out completely, especially during our brutal Texas summers.

During the active growing season, from late February through late October, give your asparagus patch about 1-2 inches of water per week, depending on rainfall. Use the finger test to check the soil moisture: stick your finger about 2 inches deep. If the soil feels dry, it's time to water. In the hottest part of the summer, you might need to water more frequently, especially if we're in a dry spell.

Water at the base of the plants to avoid wetting the foliage, which can encourage fungal diseases, especially with our variable humidity. Signs of underwatering include yellowing or wilting spears. Overwatering can lead to crown rot, so make sure your asparagus patch has good drainage.

A layer of mulch around your asparagus plants can help retain moisture in the soil and suppress weeds. Use a good organic mulch like shredded bark or compost. But be careful, fire ants love mulch, so keep an eye out for those mounds.

Asparagus pruning is minimal. The most important thing is to let the ferns grow all summer long. These ferns are what feed the crown and give you a good harvest next year.

In late fall or early spring, after the ferns have died back and turned brown, you can cut them back to ground level. Don't be tempted to cut them back earlier, as that can weaken the plant.

Also, don't harvest your asparagus for more than about 8 weeks per season. Over-harvesting can weaken the plant and reduce your yields in future years.

You can expect your first harvest of asparagus in late February through early December, about two years after transplanting those crowns. Look for spears that are 6-8 inches tall with tight, closed tips.

To harvest, simply snap the spears off at ground level. Be careful not to damage the surrounding spears or the crown of the plant. Stop harvesting when the spears start to get thin, about the diameter of a pencil. Let the remaining spears fern out to feed the plant.

To encourage continued production, water and fertilize your asparagus patch regularly throughout the harvest season. As the first frost approaches in late November, stop harvesting and let all the remaining spears fern out. This will help the plant store energy for the winter and give you a better harvest next year.

Here are three common problems you might encounter with asparagus in Texas:

Asparagus Beetle

• What it looks like: Small, metallic blue or black beetles that feed on the spears and ferns. You might also see their eggs, which are small, dark, and attached to the spears.
• What causes it: Asparagus beetles are attracted to asparagus plants, especially in the spring and summer.
• How to fix/prevent it: Handpick the beetles and eggs off the plants. You can also use insecticidal soap or neem oil. Encourage beneficial insects like ladybugs, which prey on asparagus beetles.

Crown Rot from Poor Drainage

• What it looks like: Yellowing or wilting spears, stunted growth, and a mushy, rotting crown.
• What causes it: Crown rot is caused by a fungal disease that thrives in wet, poorly drained soil. Texas's unpredictable rainfall and occasional flash floods can make this a problem.
• How to fix/prevent it: Plant asparagus in well-drained soil. Avoid overwatering. Improve drainage by adding compost or other organic matter to the soil.

Thin Spears from Over-Harvesting

• What it looks like: Spears that are thin and spindly, even when the plant is well-established.
• What causes it: Over-harvesting weakens the plant and depletes its energy reserves.
• How to fix/prevent it: Don't harvest asparagus for more than about 8 weeks per season. Let plenty of spears fern out to feed the plant. Fertilize regularly.

Texas Specific Challenges: The hot-to-extreme Texas heat can stress asparagus plants, making them more susceptible to pests and diseases. Variable humidity can also create favorable conditions for fungal diseases. Unpredictable rainfall can lead to both drought and overwatering, so it's important to monitor the soil moisture and adjust your watering schedule accordingly.

Good companions for asparagus include tomatoes, parsley, and basil. Tomatoes help protect asparagus from asparagus beetles by repelling them. Parsley attracts beneficial insects that prey on asparagus pests. Basil also repels asparagus beetles and other pests.

Avoid planting asparagus near onions and garlic. These plants can inhibit the growth of asparagus.