Rosemary in Zone 8B — Florida

Rosemary is a fantastic addition to any Florida garden. Its aromatic leaves add a distinctive flavor to your cooking, especially grilled meats and roasted vegetables. Plus, the plant itself is beautiful and drought-tolerant, making it a low-maintenance choice once established in our sandy soil.

While our hot, humid summers and occasional hurricanes present challenges, rosemary's adaptability and the reversed growing season mean you can enjoy fresh herbs nearly year-round. With a 303-day growing season, you'll find the timing works well for rosemary.

Starting rosemary from seed indoors is possible, but honestly, it can be a bit finicky here in Florida. Germination is often erratic, and the seedlings grow slowly. If you're up for the challenge, start your seeds indoors from late November through late December, about 12 weeks before you'd like to transplant them outside.

Use seed trays with a good seed-starting mix, provide consistent warmth (a heat mat helps), and ensure plenty of bright light, especially since our spring character is reversed. Bottom watering can help prevent damping-off, a common problem with seedlings in our humid environment. Honestly, though, you'll have much better luck buying established plants from a local nursery.

Transplant your rosemary seedlings outdoors in early to late March. Before planting, harden them off by gradually exposing them to outdoor conditions for about a week. This is especially important, as the weather can still be unpredictable at this time of year.

Space your plants 24-36 inches apart in a sunny spot with well-draining soil. While rosemary is drought-tolerant, it needs good drainage to prevent root rot, which is a common problem in our heavy summer rains. Honestly, rosemary is very slow and difficult from seed. Save yourself the hassle and buy established plants.

Rosemary thrives on neglect, especially in Florida's humid climate. Overwatering is a far bigger threat than underwatering, so err on the side of dryness. Once established, rosemary is very drought-tolerant.

During the cooler months, water deeply only when the top 2 inches of soil feel dry to the touch – use the finger test! In the scorching summer heat, you might need to water once a week, but only if rainfall is scarce. Aim for about 1 inch of water per week, delivered slowly at the base of the plant to avoid wetting the foliage and encouraging fungal diseases in our humid air.

Signs of underwatering include wilting or drooping leaves, while yellowing leaves can indicate overwatering. A light layer of pine straw mulch can help retain some moisture and suppress weeds, but avoid piling it up against the stem, which can trap moisture and lead to rot.

Rosemary needs minimal pruning, mostly just to maintain its shape and encourage bushier growth. After flowering, lightly prune the tips of the stems to encourage new growth. Avoid cutting into the old, woody parts of the plant, as they may not regrow.

Shape your rosemary in the spring to maintain a nice, compact form. As the first frost approaches around mid- December, don't do any heavy pruning. Just remove any dead or damaged branches.

You can start harvesting rosemary in late May through mid July, about 90 days after transplanting. Look for 4-6 inch stem tips – these are the most tender and flavorful. Never harvest more than 1/3 of the plant at any one time to avoid stressing it.

The woody stems are too tough to eat, so stick to the new growth. Regular harvesting encourages bushier growth and keeps the plant producing. As the first frost approaches in mid- December, harvest any remaining usable stems to dry or freeze for later use.

Rosemary, like many plants in Florida, faces certain challenges. The top three problems you're likely to encounter are root rot from overwatering, powdery mildew, and spider mites.

Root Rot from Overwatering

• What it looks like: Yellowing leaves, wilting even when the soil is moist, and a general decline in plant health. The roots may be brown and mushy.
• What causes it: Overwatering, especially in our poorly draining sandy soils, creates a waterlogged environment that suffocates the roots and allows fungal pathogens to thrive.
• How to fix/prevent it: Ensure your rosemary is planted in well-draining soil. Water only when the top 2 inches of soil are dry. Consider raised beds or containers to improve drainage.

Powdery Mildew

• What it looks like: White or grayish powdery coating on leaves and stems. Leaves may curl, yellow, and die.
• What causes it: Various fungi that thrive in warm days, cool nights, and moderate humidity – conditions we often experience in Florida, especially during the transition seasons.
• How to fix/prevent it: Improve air circulation around your plants by spacing them properly and pruning to open up the canopy. Remove affected leaves promptly. Neem oil or potassium bicarbonate sprays can help control the spread. A milk spray (1 part milk to 9 parts water) can also be surprisingly effective.

Spider Mites

• What it looks like: Fine stippling (tiny white dots) on leaves, fine webbing on leaf undersides and between stems, and leaves turning bronze or yellow.
• What causes it: Tiny arachnids that thrive in hot, dry conditions. Populations can explode during periods of drought stress, which can happen even in our humid climate.
• How to fix/prevent it: A strong spray of water (daily for a week) is often the best initial treatment. Increase humidity around your plants. Neem oil or insecticidal soap can also be effective.

Florida Specific Challenges: Rosemary can be tricky in Florida because of our hot heat, very-high humidity, and wet-summer rainfall. These conditions create a perfect storm for fungal diseases and root rot. Be vigilant about watering practices and choose a well-drained location to give your rosemary the best chance of success.

Companion planting can really help rosemary thrive in your Florida garden. Rosemary pairs well with sage, thyme, and lavender because they all share similar needs: full sun and well-drained soil. Planting rosemary near green beans and carrots can also be beneficial, as rosemary is believed to repel certain pests that attack these vegetables.

Avoid planting rosemary near mint. Mint is very aggressive and can quickly take over, crowding out your rosemary and competing for resources. Plus, mint prefers moist soil, which is the opposite of what rosemary needs.