Arugula in Zone 8B — Texas

Arugula, with its peppery bite, adds a zing to salads, sandwiches, and even pizzas. Here in Texas, it's a fantastic crop to grow because you can squeeze in both a spring and fall harvest, dodging the worst of the Texas heat. Plus, fresh arugula tastes worlds better than the stuff you get at the store.

Sure, our unpredictable weather can throw curveballs, but with a little planning, you can enjoy a steady supply of this leafy green. Our long growing season—273 days, give or take—means you have plenty of opportunities to get it right, even if a late freeze or early heat wave tries to interfere.

Starting arugula indoors isn't essential, but it can give you a head start, especially for that early spring crop. Sow seeds indoors from mid January through early February, about three weeks before you plan to transplant. Use seed trays with a good seed-starting mix, and keep them in a warm spot with plenty of light – a sunny windowsill or under grow lights works great.

Water from the bottom to avoid damping off; just set the tray in a shallow dish of water until the soil surface is moist. Because our springs can come on fast, getting those seedlings going indoors can help you plant early, harvest early, and beat the worst of the heat.

Transplant your arugula seedlings outdoors from mid February through late March. Before you plant, harden them off by gradually exposing them to outdoor conditions for about a week. This helps them adjust to the Texas sunshine and wind.

Space them about 6 inches apart in well-drained soil. Keep an eye on the forecast – a late freeze can still happen, so be ready to cover them if temperatures drop.

Direct sowing arugula is super easy and often the preferred method, especially for a continuous harvest. Sow seeds directly into the garden from late January through early October. Arugula is fast-growing, so you'll see sprouts in just a few days.

Prepare the soil by loosening it and removing any rocks or debris. Sow seeds about ¼ inch deep and 6 inches apart. Keep the soil consistently moist, especially during germination. The downside of direct sowing is that arugula bolts quickly in the heat, so focus on cool weather plantings for the best results.

Arugula needs consistent moisture to thrive, but it doesn’t like to be waterlogged. In the Texas climate, watering can be tricky because of our unpredictable rainfall and hot-to-extreme summer heat. During the spring and fall, when temperatures are milder, aim for about 1 inch of water per week, either from rain or irrigation.

Stick your finger about 2 inches deep into the soil. If it feels dry, it's time to water. During the hotter months, you might need to water more frequently, especially if you're experiencing a dry spell. Watering at the base of the plant is best to avoid wetting the leaves, which can encourage fungal diseases, especially with our variable humidity.

Signs of underwatering include wilting leaves and slow growth. Overwatering can lead to yellowing leaves and root rot. A layer of mulch can help retain moisture and keep the soil cool, which is especially important during the summer months.

You can expect your first arugula harvest about 40 days after planting, which here in Texas means you can be harvesting from early March through early December, depending on when you planted. The leaves are ready to harvest when they're about 2-3 inches long. Younger leaves have a milder flavor, while larger leaves are more peppery.

To harvest, simply snip off the outer leaves with scissors, leaving the inner leaves to continue growing. This encourages continuous production. Keep harvesting regularly to prevent the plant from bolting, especially as temperatures rise. As the first frost approaches in late November, harvest any remaining leaves, as they'll likely be damaged by the cold.

Here are the most common problems you'll face growing arugula in Texas:

Flea Beetles

• What it looks like: Tiny round holes (shot-hole pattern) in leaves, especially on young seedlings. You might see small, dark beetles jumping when disturbed.
• What causes it: These small jumping beetles feed on leaves, causing damage. They are most active in spring and early summer.
• How to fix/prevent it: Use row covers to protect seedlings. Delay planting until plants are larger and more resilient. Spray with kaolin clay or neem oil. Interplant with basil or catnip to deter them.

Bolting in Heat

• What it looks like: The plant sends up a flower stalk, and the leaves become tough and bitter.
• What causes it: Arugula is a cool-season crop and bolts when temperatures consistently exceed 80°F.
• How to fix/prevent it: Time plantings for cool weather in spring and fall. Choose bolt-resistant varieties. Provide shade during warm spells. Mulch to keep soil cool. Harvest leaves frequently to delay bolting.

Aphids

• What it looks like: Clusters of tiny green, black, or white insects on stems and leaf undersides. Sticky honeydew residue and curled or distorted new growth.
• What causes it: Aphids are sap-sucking insects that thrive in warm weather.
• How to fix/prevent it: Spray aphids off with a strong stream of water. Encourage natural predators like ladybugs and lacewings. Use insecticidal soap or neem oil. Avoid over-fertilizing with nitrogen.

Downy Mildew

• What it looks like: Yellow patches on leaf tops with fuzzy gray-purple growth on undersides. Leaves brown and die from the bottom up.
• What causes it: A fungal disease that spreads in cool, humid conditions.
• How to fix/prevent it: Remove affected leaves immediately. Improve air circulation. Water at the base of the plant, never overhead. Use copper-based fungicides.

Texas Specific Challenges: The hot-to-extreme heat in our summers makes bolting a major concern, so timing your plantings is crucial. Variable humidity can also contribute to fungal diseases like downy mildew. Unpredictable rainfall means you need to be vigilant about watering, ensuring your arugula gets enough moisture without being waterlogged. And keep an eye out for fire ants, as they can disrupt seedlings.

Arugula plays well with other garden veggies. Lettuce and spinach are good companions because they share similar growing requirements and don't compete for resources. Carrots and beets are also beneficial neighbors, as they help to loosen the soil, making it easier for arugula roots to grow. Onions can help deter pests, keeping your arugula patch healthier.

Avoid planting arugula near strawberries. Strawberries are susceptible to certain fungal diseases that can spread to arugula, especially in our humid Texas conditions.