Celery in Zone 8B — Florida

Celery might not be the first thing that comes to mind for a Florida garden, but fresh, crisp stalks straight from your backyard are far superior to anything you'll find in the store. Plus, it's incredibly versatile in the kitchen and surprisingly satisfying to grow your own. The Florida gardening calendar is different, and growing celery allows you to have fresh produce when other gardens are slowing down.

Our subtropical climate does present challenges like extreme humidity and sandy soil, but with careful timing, you can absolutely grow celery here in Zone 8B. We have a long growing season, around 303 days, so you can plant in fall and harvest in late spring before the worst of the summer heat arrives.

Starting celery indoors is almost essential here in Florida. Get those seeds going late November through late December, about 10 weeks before you plan to transplant. Celery seeds are tiny and need light to germinate, so don't bury them too deep.

Use seed trays with a good seed-starting mix and keep them consistently moist. Bottom watering is especially helpful to avoid disturbing the seeds. Place your trays under grow lights or in a very bright window, and maintain a temperature around 70-75°F. Remember, our spring character is reversed, so starting early is key to getting a good harvest before the summer heat sets in.

Transplant your celery seedlings into the garden mid-February through mid-March. Before you do, harden them off for about a week by gradually exposing them to outdoor conditions. This helps them adjust to the Florida sun and wind.

Space your celery plants about 8-10 inches apart in rows. Keep an eye on the weather – a late cold snap can happen, even in Florida, so be prepared to cover your seedlings if temperatures dip near freezing.

Celery is a very thirsty plant, and consistent watering is crucial for success in Florida's climate. This is probably the most important part of growing celery here. With our hot summers and sandy soil, you'll need to stay on top of it.

During the cooler months, aim for at least 1-1.5 inches of water per week. Once the temperatures start to rise in spring, increase that to 2 inches or more. Check the soil moisture regularly with the "finger test" – stick your finger about 2 inches deep, and if the soil feels dry, it's time to water. Water at the base of the plants rather than overhead to minimize fungal diseases, which are a big concern with our very-high humidity.

Signs of underwatering include wilting leaves and bitter-tasting stalks. Overwatering can lead to root rot, so make sure your soil is well-draining. A layer of mulch around the plants helps retain moisture and suppress weeds, but be mindful of keeping the mulch away from the stems to prevent rot.

You can expect to start harvesting your celery from mid-May through late June, about 85 days after transplanting. Look for stalks that are at least 8 inches long. You can either harvest individual outer stalks as needed, or cut the entire plant at the base once the stalks reach about 12 inches.

For a milder flavor, blanch the stalks by mounding soil around them a week or two before harvest. To encourage continued production, harvest outer stalks first, allowing the inner stalks to keep growing. As our first frost approaches around mid- December, harvest any remaining celery, as it won't tolerate freezing temperatures.

Celery can be tricky, and here are some common problems we face in Florida:

Bolting from temperature stress

• What it looks like: The plant prematurely sends up a flower stalk. The stalks become bitter and tough.
• What causes it: Fluctuations in temperature, especially a sudden shift from cool to hot. This can be common during Florida's spring.
• How to fix/prevent it: Choose bolt-resistant varieties. Provide consistent watering and some shade during the hottest part of the day.

Hollow stalks

• What it looks like: The inside of the celery stalk is empty or has large air pockets.
• What causes it: Inconsistent watering, nutrient deficiencies (especially boron), or excessively high temperatures.
• How to fix/prevent it: Maintain consistent soil moisture, fertilize with a balanced fertilizer, and provide shade during the hottest part of the day. Consider a foliar spray of boron if a deficiency is suspected.

Stringy stalks from heat

• What it looks like: The celery stalks are tough and fibrous, making them unpleasant to eat.
• What causes it: High temperatures, especially during the later stages of growth.
• How to fix/prevent it: Choose heat-tolerant varieties, provide shade during the hottest part of the day, and ensure consistent watering. Harvest promptly once the celery is mature.

Florida Specific Challenges: The combination of hot heat, very-high humidity, and wet-summer rainfall creates a breeding ground for fungal diseases that can devastate celery. Nematodes in our sandy soil can also be a problem. Focus on good soil health, proper watering, and disease-resistant varieties to minimize these issues.

Companion planting can be a great way to improve your celery crop here in Florida. Green beans are a good companion because they fix nitrogen in the soil, which benefits celery. Cabbage family plants also do well near celery, as celery can help deter cabbage moths.

Tomatoes and onions are also good companions. Tomatoes provide some shade, and onions can help repel certain pests. Avoid planting carrots near celery, as they compete for the same nutrients in the soil.