Cabbage in Zone 10B — Florida

Cabbage is a rewarding crop to grow in Florida, especially when you're craving fresh, homegrown flavors during our cooler months. Its crisp texture and mild sweetness make it incredibly versatile in the kitchen, perfect for slaws, stir-fries, or even a simple side dish. There's nothing quite like the satisfaction of harvesting a beautiful head of cabbage you've nurtured yourself.

Our Florida gardening calendar is different, and while the humidity and occasional pests can be a challenge, the timing for cabbage is ideal. We can take advantage of our extended 360-day growing season and plant in fall for a winter harvest, avoiding the worst of the summer heat and humidity.

To get a head start on your cabbage crop, start seeds indoors from early to late November. This gives the seedlings about 6 weeks to develop before transplanting. Use seed trays filled with a good quality seed starting mix.

Keep the trays in a warm location with plenty of light, either from a sunny window or a grow light. Bottom watering is a great way to keep the soil consistently moist without overwatering, which is especially helpful in our humid climate. Remember, our spring is reversed, so we're starting seeds indoors during what feels like the tail end of the traditional growing season up north.

Transplant your cabbage seedlings outdoors from late December through mid January. Before transplanting, harden them off by gradually exposing them to outdoor conditions for about a week. This helps them adjust to the Florida sunshine and temperatures.

When transplanting, space the seedlings 12-18 inches apart in rows. This allows them enough room to grow into full-sized heads. Keep an eye on the weather during this time, as we can sometimes get unexpected cold snaps.

Cabbage needs consistent moisture to thrive, but overwatering can be just as detrimental, especially with our high humidity. Aim to keep the soil evenly moist, but not waterlogged. A good rule of thumb is to water when the top 2 inches of soil feel dry to the touch – the "finger test".

During our drier fall and winter months, this might mean watering deeply once or twice a week, providing about 1-1.5 inches of water each time. Avoid overhead watering as much as possible, as our humid conditions can promote fungal diseases; water at the base of the plants instead. If we have a particularly dry spell, increase watering frequency. Conversely, during our wet-summer-like weeks, you may not need to water at all.

Signs of underwatering include wilting leaves, while yellowing leaves and stunted growth can indicate overwatering. Mulching around your cabbage plants with pine straw or wood chips helps retain moisture and suppress weeds, which is a win-win in Florida gardens. Remember, heavy watering after a dry period can cause the heads to split, so consistent moisture is key.

Your cabbage should be ready to harvest from early March through mid April, about 70 days after transplanting. The best indicator of ripeness is the firmness of the head. When you gently squeeze the cabbage head, it should feel solid and dense.

Also, make sure that the head has reached the full size expected for the variety you are growing. To harvest, use a sharp knife to cut the head off at the base of the plant. Leaving the outer leaves intact can sometimes encourage smaller side shoots to develop, giving you a small bonus harvest. As our late December frost approaches, harvest any remaining heads that are close to maturity to avoid damage.

Here are some common problems you might encounter growing cabbage in Florida:

• Cabbage Worms
• What it looks like: Smooth green caterpillars on brassica leaves. Irregular holes chewed in leaves. Dark green droppings. White butterflies hovering around plants.
• What causes it: Larvae of white cabbage butterflies. Multiple generations per season in our warm climate.
• How to fix/prevent it: Bt spray is very effective. Floating row covers prevent egg laying. Handpick caterpillars. Interplant with aromatic herbs (thyme, sage). Encourage parasitic wasps.
• Cabbage Loopers
• What it looks like: Similar to cabbage worms, but these caterpillars move with a looping motion. They also chew holes in leaves and can defoliate plants.
• What causes it: These are the larvae of a moth. Like cabbage worms, they thrive in our warm climate and can have multiple generations.
• How to fix/prevent it: Bt spray is effective against loopers as well. Handpicking is also an option. Encourage beneficial insects like lacewings and parasitic wasps.
• Splitting
• What it looks like: The cabbage head cracks open.
• What causes it: Inconsistent watering. A period of drought followed by heavy rain or irrigation causes the head to swell too quickly.
• How to fix/prevent it: Maintain consistent soil moisture. Mulch around plants to help retain moisture. If heavy rain is expected, consider lightly scoring the base of the head to relieve pressure.
• Clubroot
• What it looks like: Stunted growth, wilting in afternoon heat, yellowing leaves. Roots are swollen, distorted, and club-shaped when dug up.
• What causes it: Soil-borne pathogen (*Plasmodiophora brassicae*) that persists in soil for 10+ years. Favors acidic, wet soil.
• How to fix/prevent it: Raise soil pH to 7.0-7.2 with lime. Improve drainage. Rotate brassicas on a 7-year cycle. Remove and destroy infected plants (don't compost). Start transplants in sterile mix.

Florida Specific Challenges: Our hot heat, very-high humidity, and wet-summer rainfall create a perfect environment for fungal diseases and pests. Good air circulation, proper watering techniques, and vigilant monitoring are key to success with cabbage in Florida. Also, sandy soil can be amended with compost to improve water retention.

Companion planting can be a great way to improve the health and yield of your cabbage. Green beans are good companions because they fix nitrogen in the soil, which benefits cabbage. Celery helps to repel cabbage white butterflies, reducing the risk of cabbage worms.

Onions deter many pests with their strong scent. Potatoes don't directly benefit the cabbage, but they don't compete for the same nutrients and can help break up the soil. Dill attracts beneficial insects like ladybugs and hoverflies, which prey on aphids and other pests. Avoid planting cabbage near tomatoes, strawberries, or peppers, as they can stunt the growth of the cabbage. These plants compete for nutrients and can attract similar pests.