Mustard Greens in Zone 6B — Texas

Mustard greens offer a peppery bite that's fantastic in salads, stir-fries, or even braised as a side. They're quick to mature, making them a rewarding crop for Texas gardeners looking for a fast turnaround, and you can keep harvesting them as needed. Plus, they thrive in the cooler parts of our long growing season, giving you a delicious and nutritious harvest when other plants are struggling in the Texas heat.

Our unpredictable weather can be a challenge, with temperature swings and the occasional late freeze. But with a little planning, you can easily fit mustard greens into our 230-day growing season. Focus on planting during those cooler windows and you'll be enjoying fresh greens in no time.

Starting mustard greens indoors is definitely an option, especially if you're aiming for that early spring harvest. Begin your seeds indoors from mid February through early March, 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 well. Don't forget to water from the bottom to prevent damping off. Starting them indoors gives you a head start, especially with our early spring weather patterns.

Transplant your mustard greens seedlings outdoors from mid March through late April, after hardening them off for about a week. Hardening off simply means gradually exposing them to outdoor conditions.

Space them 6-12 inches apart in well-drained soil. Keep an eye on the weather forecast; those late cold snaps can still happen, so be ready to cover your seedlings if needed.

Direct sowing mustard greens is easy and effective, and it allows you to take advantage of our long growing season. Sow seeds directly into the garden from late February through mid September.

Make sure the soil is loose and the temperature is consistently above 40°F. Plant seeds about ½ inch deep, spacing them 6-12 inches apart or thinning later. Direct sowing is great because you don't have to worry about disturbing the roots during transplanting.

Mustard greens need consistent moisture, especially in our Texas climate. While they're not drought-tolerant, they also don't like soggy soil.

During the spring and fall, when temperatures are milder, aim for about 1 inch of water per week. In the heat of summer, you might need to increase that to 1.5-2 inches, depending on rainfall. Stick your finger about 2 inches deep into the soil; if it feels dry, it's time to water. When humidity is high, watering at the base of the plants is better than overhead watering.

Underwatering will cause the leaves to become tough and spicier than normal, and can trigger bolting. Overwatering can lead to root rot, so make sure your soil drains well. A layer of mulch, like shredded leaves or straw, can help retain moisture and keep the soil cool, which is especially important during our brutal Texas heat.

You can expect your first harvest of mustard greens about 45 days after planting, so from mid April through mid November, depending on when you planted. Young leaves are milder and more tender, while larger leaves will have a spicier, more pungent flavor.

Harvest by snipping off the outer leaves, leaving the inner ones to continue growing. This encourages continuous production. Make sure to harvest before the plant starts to flower, as this will cause the leaves to become bitter.

As the first frost approaches around early November, harvest any remaining leaves. While mustard greens can tolerate a light frost, a hard freeze will damage them.

Mustard greens, like any crop, can face challenges. Here are a few common problems and how to tackle them in Texas:

Flea Beetles

• What it looks like: Tiny round holes in the leaves, giving them a "shot-hole" appearance. You'll see small, dark beetles jumping around when disturbed.
• What causes it: Small jumping beetles that feed on the leaves, especially on young seedlings.
• How to fix/prevent it: Use row covers to protect seedlings. Delay planting until plants are larger and more resilient. Kaolin clay coating can deter them. Neem oil spray can also help.

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: Rapidly reproducing sap-sucking insects that thrive in warm weather.
• How to fix/prevent it: A strong spray of water can knock them off. Encourage ladybugs and lacewings, which are natural predators. Insecticidal soap is effective for heavy infestations.

Cabbage Worms

• What it looks like: Smooth green caterpillars chewing irregular holes in the leaves. Dark green droppings. White butterflies flying around your plants.
• What causes it: Larvae of white cabbage butterflies.
• How to fix/prevent it: Bt spray is very effective. Floating row covers prevent the butterflies from laying eggs. Handpick caterpillars when you see 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: Extended warm temperatures, especially when days consistently exceed 80°F.
• How to fix/prevent it: Time your plantings for cooler weather in spring and fall. Choose bolt-resistant varieties. Provide shade during hot spells. Mulch to keep the soil cool.

Texas Specific Challenges: The extreme heat, variable humidity, and unpredictable rainfall in Texas can exacerbate these problems. Flea beetles and aphids thrive in warm weather. Bolting is a constant threat during our long, hot summers. Consistent monitoring and timely intervention are key to keeping your mustard greens healthy and productive.

Companion planting can really boost your mustard green crop. Onions and garlic are great companions because their strong scent deters pests like aphids and flea beetles. Beets are also beneficial, as they don't compete for the same nutrients and can help loosen the soil. Dill attracts beneficial insects that prey on pests, and lettuce provides ground cover, helping to retain moisture in our sometimes dry climate.

Avoid planting mustard greens near strawberries or tomatoes. Strawberries are susceptible to some of the same pests that attack mustard greens, potentially increasing pest pressure. Tomatoes can inhibit the growth of mustard greens, so it's best to keep them separate.