Bok Choy in Zone 9A — Texas

Bok choy is a fantastic addition to your Texas garden, offering a mild, slightly sweet flavor that’s delicious stir-fried, steamed, or added to soups. Its quick growth and versatility in the kitchen make it a rewarding crop, and you can even get two harvests – one in spring and another in the fall – taking advantage of our long growing season.

Sure, we have our share of challenges here in Texas, from the brutal Texas heat to unpredictable weather. But with a little planning and attention to timing, you can successfully grow bok choy. Our long, 293-day growing season gives you plenty of opportunities to get it right.

Starting bok choy indoors is an option, especially if you want a head start on the spring or fall growing season. You can start seeds indoors from mid January through early February, about four weeks before you plan to transplant. Use seed trays with a good seed-starting mix, and keep them in a warm location with plenty of light – a sunny windowsill or under grow lights works well.

Bottom watering is your friend when starting seeds. Set the tray in a shallow dish of water and let the soil soak it up from the bottom; this encourages strong root growth and avoids damping off. Since spring comes early here, starting indoors gives you a jump on the season.

Transplant your bok choy seedlings outdoors from mid February through late March, once the danger of a hard freeze has passed. Before transplanting, harden off your seedlings by gradually exposing them to outdoor conditions for about a week. This helps them adjust to the Texas sun and wind.

Plant seedlings 6-10 inches apart in well-drained soil. Keep an eye on the weather forecast, as we can still get some unexpected cold snaps during this time. A frost blanket can protect your young plants if needed.

Direct sowing is a simple way to grow bok choy, especially for a fall crop. Sow seeds directly into the garden from early February through early October. Just be sure to amend your soil with compost to improve drainage and fertility.

Bok choy seeds germinate best when the soil temperature is between 50°F and 70°F. Plant seeds about ¼ inch deep and 6-10 inches apart. Thin seedlings as needed to give them enough space to grow. The advantage of direct sowing is you avoid transplant shock, but you'll need to keep a close eye on soil moisture.

Bok choy needs consistent moisture to thrive in our Texas climate. Aim to keep the soil evenly moist, but not waterlogged. The "finger test" is a good way to check: stick your finger about 2 inches deep into the soil. If it feels dry, it's time to water.

During the hotter months, you may need to water deeply every other day, providing about 1 inch of water per week. In the cooler spring and fall, you can usually get away with watering a couple of times a week. Water at the base of the plants to avoid wetting the leaves, which can encourage fungal diseases, especially when our humidity spikes.

Signs of underwatering include wilting leaves and slow growth. Overwatering can lead to yellowing leaves and root rot. A good layer of mulch, like shredded leaves or pine straw, can help retain moisture and keep the soil cool during the brutal Texas heat.

You can expect your first harvest of bok choy from mid March through mid December, about 45 days after planting. You can harvest baby bok choy when the leaves are 6-8 inches tall or wait for the full-sized heads to reach 12-15 inches. Look for firm, crisp leaves as a sign of ripeness.

To harvest, cut the entire head of bok choy above the base. If you leave the base intact, it may produce new leaves for a second harvest. Continuous harvesting of outer leaves also works well.

As our first frost approaches in early December, harvest any remaining bok choy, even if it's not fully mature. You can use it in soups or stir-fries. If you're lucky, and the freeze isn't too severe, your bok choy might even survive for a bit longer with some protection.

Here are some common problems you might encounter growing bok choy in Texas:

Flea Beetles

• What it looks like: Tiny round holes (shot-hole pattern) in the leaves, especially on young seedlings. You might see small dark beetles jumping when disturbed.
• What causes it: These tiny jumping beetles feed on the leaves, causing damage that can weaken or even kill young plants. They thrive in warm, dry conditions.
• How to fix/prevent it: Use row covers to protect seedlings during their vulnerable stage. You can also delay planting until plants are larger and more resilient. A coating of kaolin clay can deter them, and neem oil spray can help control infestations. Interplanting with basil or catnip may also help repel them.

Cabbage Worms

• What it looks like: Smooth green caterpillars chewing irregular holes in the leaves. You might also see dark green droppings and white butterflies hovering around your plants.
• What causes it: These are the larvae of white cabbage butterflies. They can go through multiple generations in our long, warm growing season.
• How to fix/prevent it: Bt spray is very effective against cabbage worms. Floating row covers can prevent the butterflies from laying eggs on your plants. Handpicking caterpillars is also an option. Interplanting with aromatic herbs like thyme or sage can help deter the butterflies.

Slugs

• What it looks like: Irregular holes in the leaves, particularly on low-growing plants. You might also see silvery slime trails on the leaves and soil. Damage is worse at night and in wet weather.
• What causes it: Slugs are gastropods that feed at night in moist conditions. They hide under mulch, boards, and debris during the day.
• How to fix/prevent it: Beer traps (shallow dishes of beer sunk into the soil) can attract and drown slugs. Iron phosphate bait is another option that's pet-safe. Remove any hiding spots like boards or debris. Water in the morning so the soil surface dries out by evening. Copper tape around beds and diatomaceous earth around plants can also deter slugs.

Bolting in Heat

• What it looks like: The plant sends up a flower stalk, and the leaves become tough and bitter. Harvest quality declines significantly.
• What causes it: Bok choy is a cool-season crop that bolts (goes to seed) when temperatures rise. This is especially common during our hot Texas summers.
• How to fix/prevent it: Time your plantings for cool weather in the spring and fall. Choose bolt-resistant varieties if possible. Provide shade during warm spells with shade cloth. Mulch to keep the soil cool. Harvest your bok choy before bolting progresses too far.

Texas Specific Challenges: The hot-to-extreme heat, variable humidity, and unpredictable rainfall in Texas can make growing bok choy a bit tricky. The heat can cause bolting, while humidity can increase the risk of fungal diseases. Unpredictable rainfall can lead to either drought stress or waterlogged soil. Careful monitoring and adjustments to your watering and shading strategies are essential for success. And don't forget to watch out for those fire ants when you're tending your garden!

Good companions for bok choy include garlic and onions. These alliums help to repel pests like aphids and cabbage worms with their strong scent. Beets are also beneficial, as they don't compete for the same nutrients in the soil and can help improve soil structure. Lettuce and spinach are good neighbors because they have different growth habits and nutrient needs, reducing competition.

Avoid planting bok choy near strawberries or tomatoes. Strawberries can attract slugs, which will then feast on your bok choy. Tomatoes can attract pests like aphids and whiteflies, which can also infest your bok choy. Plus, they both prefer slightly acidic soil, whereas bok choy does best in soil that is neutral to slightly alkaline.