Cabbage in Zone 9B — Florida

Cabbage is a rewarding crop to grow in Florida, offering a satisfying crunch and mild flavor that's perfect for slaws, stir-fries, and more. The taste of a freshly harvested cabbage, grown right in your own backyard, is far superior to anything you'll find at the grocery store. Plus, the Florida gardening calendar is different – we plant in fall, harvest in winter, and cabbage thrives in our cooler months.

Sure, we have our challenges, like humidity and the occasional nematode issue, but with careful timing, you can easily grow beautiful heads of cabbage. Our long, 344-day growing season gives you ample opportunity to enjoy a bountiful harvest. Summer is the slow season, but fall through spring is prime time for cool-season crops like cabbage.

Starting cabbage indoors gives you a head start on the growing season. Here in Florida, that means sowing your seeds from mid-November through early December, about six weeks before you plan to transplant them outside. Use seed trays filled with a good quality seed-starting mix.

Keep the trays warm and provide plenty of light – a grow light works great. Bottom watering is especially helpful at this stage, as it encourages strong root development and prevents damping-off, which can be a problem in our humid climate. Remember, our spring character is reversed, so we're preparing for our cool-season crops while other gardeners are just starting their warm-season ones.

Transplant your cabbage seedlings outdoors from early January through early February. Before you do, harden them off by gradually exposing them to outdoor conditions for about a week. This helps them adjust to the sun and wind, preventing transplant shock.

When you're ready to plant, space your seedlings 12-18 inches apart in well-drained soil. Be mindful of the weather at this time of year; we can sometimes have unexpected warm spells or even a late frost, so keep an eye on the forecast and be prepared to cover your plants if necessary.

Consistent watering is key to growing healthy cabbage in Florida. While cabbage isn't drought-tolerant, overwatering can be just as detrimental, especially with our high humidity. During our drier fall and winter months, aim to give your cabbage patch about 1 inch of water per week, either from rainfall or irrigation.

Use the "finger test" to check the soil moisture – stick your finger about 2 inches deep, and 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. During the wet-summer months, you may not need to water at all, but keep an eye on the soil moisture.

Signs of underwatering include wilting leaves and slow growth. Overwatering can lead to yellowing leaves and root rot. A layer of mulch, like pine straw or wood chips, can help retain moisture in the soil and suppress weeds, which is especially important in our sandy soils.

You can expect your first cabbage harvest from mid-March through early May, about 70 days after transplanting. The best way to tell if a cabbage is ready to harvest is to gently squeeze the head. It should feel firm and solid, not soft or spongy.

Also, make sure it has reached the full size expected for its variety. To harvest, use a sharp knife to cut the cabbage head at its base, leaving a few outer leaves on the stem. This can sometimes encourage the plant to produce smaller side shoots, giving you a second, smaller harvest.

As our first frost approaches in late December, you may still have some smaller cabbages in the garden. These are frost-hardy, so they can withstand a light frost, but if a hard freeze is predicted, harvest them even if they're not quite fully mature. They'll still be delicious!

Cabbage can face a few problems here in Florida, but knowing what to look for can help you stay ahead of the game. Here are some common issues:

• 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 mean they can be a persistent problem.
• 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 loopers move in a distinctive looping motion. They also chew holes in leaves, leaving behind droppings.
• What causes it: These are the larvae of a moth and, like cabbage worms, thrive in our warm climate.
• How to fix/prevent it: Bt spray is effective against loopers as well. Handpicking is also an option. Encourage beneficial insects like lacewings and ladybugs.
• Splitting
• What it looks like: The cabbage head cracks or splits open.
• What causes it: Inconsistent watering. Heavy watering after a period of drought is a common culprit. The cabbage head grows too quickly, causing the outer leaves to burst.
• How to fix/prevent it: Maintain consistent soil moisture. Water regularly, especially during dry spells. Harvest cabbage as soon as it's mature to prevent it from splitting.
• 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 can exacerbate fungal diseases and pest problems in cabbage. Good air circulation, proper watering techniques, and vigilant monitoring are crucial for success.

Companion planting can be a great way to boost your cabbage crop and deter pests. Green beans are excellent companions because they fix nitrogen in the soil, which benefits cabbage. Celery also works well because its strong scent can repel cabbage moths.

Onions are another good choice, as they deter many common pests. Potatoes can help improve soil structure, and dill attracts beneficial insects that prey on cabbage worms. Avoid planting cabbage near tomatoes, strawberries, or peppers, as they can compete for nutrients or attract similar pests. For instance, tomatoes and cabbage both susceptible to similar fungal diseases in our humid climate.