Bok Choy in Zone 7B — Southeast

Bok choy is a fantastic addition to your Southeast garden. Its mild, slightly sweet flavor shines in stir-fries, soups, and salads, and it's surprisingly easy to grow here. Plus, harvesting your own fresh bok choy is incredibly satisfying, especially when you can pop outside and grab it even as the weather starts to cool.

Our long growing season in the Southeast means you can get multiple harvests of bok choy with careful planning. Yes, we have to deal with the humidity and heat, but with a little attention to timing and watering, you can enjoy homegrown bok choy for a good chunk of our 235-day growing season.

Starting bok choy indoors gives you a head start, but it's not always necessary given our long growing season. If you want to get a jump on spring, start seeds indoors from mid-February through early March, about four weeks before you plan to transplant.

Use seed trays with a good seed-starting mix and provide warmth (a heat mat helps) and plenty of light (grow lights are ideal). Water gently, and consider bottom-watering to prevent damping-off – set the tray in a shallow pan of water and let the soil absorb it from the bottom. With our moderate springs, this gives you some extra control.

Transplant your bok choy seedlings outdoors from mid-March through early May. Before you plant, harden them off by gradually exposing them to outdoor conditions for about a week.

Space the plants 6-10 inches apart to allow room for growth. Keep an eye on the weather; those late cold snaps we sometimes get in early spring can stress young transplants.

Direct sowing is a perfectly viable option for bok choy in the Southeast, and it's often the easiest way to go. Sow seeds directly into well-prepared soil from early March through mid-September.

Make sure the soil is loose and the temperature is consistently above 50°F. Plant seeds about ¼ inch deep and space them 6-10 inches apart. Thin seedlings as needed. Direct sowing avoids transplant shock, but you’ll need to stay on top of weed control.

Bok choy needs consistent moisture, especially in our hot and humid Southeast climate. Aim for about 1 inch of water per week, either from rainfall or irrigation.

The finger test is your friend: stick your finger into the soil about 2 inches deep; if it feels dry, it's time to water. Water at the base of the plants to avoid wetting the leaves, which can encourage fungal diseases in our humid environment. Avoid overhead watering, especially in the evenings.

During the hotter months, you might need to water more frequently, possibly every other day. Wilting leaves are a sign of underwatering, while yellowing leaves can indicate overwatering. A layer of mulch, like pine straw (readily available here), helps retain moisture and keeps the soil cooler, which is crucial for preventing bolting.

You can start harvesting bok choy as early as mid-April if you started seeds indoors, and you can continue harvesting well into November. Bok choy is ready to harvest about 45 days after planting.

Harvest baby bok choy when the leaves are 6-8 inches tall, or wait for the full size of 12-15 inches. Cut the plant above the base, leaving the roots intact, and it will often regrow for a second harvest.

As our first frost approaches in early November, harvest any remaining bok choy, even if it's small. You can blanch and freeze it for later use in soups and stir-fries.

Here are some common problems you might encounter with bok choy in the Southeast:

Flea Beetles

• What it looks like: Tiny round holes (shot-hole pattern) in leaves, especially on young plants. You might see small, dark beetles jumping when disturbed.
• What causes it: Small jumping beetles that feed on leaves. They thrive in warm weather and can be especially problematic in spring.
• 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.

Cabbage Worms

• What it looks like: Smooth green caterpillars on the leaves, irregular holes chewed in the leaves, dark green droppings, and white butterflies hovering around your plants.
• What causes it: The larvae of those pretty white cabbage butterflies. They love our long growing season, meaning multiple generations can wreak havoc.
• How to fix/prevent it: Bt spray is very effective. Floating row covers can prevent the butterflies from laying eggs. Handpick the caterpillars whenever you see them. Interplant with aromatic herbs like thyme and sage to confuse the butterflies.

Slugs

• What it looks like: Irregular holes in leaves, especially on low-growing plants, and silvery slime trails on leaves and soil. Damage is worse at night and in wet weather.
• What causes it: These gastropods feed at night in moist conditions. They love our humid climate and hide under mulch, boards, and debris during the day.
• How to fix/prevent it: Beer traps (shallow dish of beer sunk into the soil) work well. Use iron phosphate bait (it's pet-safe). Remove hiding spots. Water in the morning so the soil surface dries out by evening. Copper tape around beds and diatomaceous earth around plants can also help.

Bolting in Heat

• What it looks like: Your bok choy starts to send up a flower stalk, and the leaves become tough and bitter.
• What causes it: Extended warm temperatures. Bok choy is a cool-season crop and bolts when temperatures 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 warm spells. Mulch heavily to keep the soil cool. Harvest before bolting progresses too far.

Southeast Specific Challenges: The combination of hot heat, humid humidity, and wet-summer rainfall in the Southeast creates a perfect environment for fungal diseases and pests. Consistent monitoring, proper watering techniques, and preventative measures are essential for a successful bok choy harvest.

Good companions for bok choy include garlic and onions, whose pungent scents deter pests like aphids and cabbage moths. Beets help loosen the soil, making it easier for bok choy roots to thrive, and lettuce and spinach provide ground cover, suppressing weeds and keeping the soil cool.

Avoid planting bok choy near strawberries, as they can attract slugs, which will then feast on your bok choy. Tomatoes are also poor companions because they compete for nutrients and can attract pests that also affect bok choy.