Arugula in Zone 10A — Florida

Arugula's peppery bite adds a zesty flavor to salads and sandwiches, and it's a surprisingly easy crop to grow here in Zone 10A. Plus, you can harvest baby greens in just a few weeks, making it a quick win during our mild winters. There's real satisfaction in snipping fresh greens from your own garden when the rest of the country is bundled up!

Our Florida gardening calendar is different, and summer is the slow season. But don't let that scare you! Arugula thrives when you plant in fall and harvest in winter. With our long growing season, you have plenty of time to enjoy this delicious green before the heat kicks in.

Starting arugula indoors is an option, but honestly, it's so easy to direct sow here that it's often unnecessary. Still, if you want a head start, you can start seeds indoors from late November through mid December, about 3 weeks before you'd like to transplant. Use seed trays with a good seed-starting mix, keep them warm (around 70°F), and provide plenty of light.

Bottom watering is key to prevent damping off, especially with our high humidity. Just set the tray in a shallow dish of water and let the soil absorb it from the bottom. Remember, our spring is reversed, so you're doing this as the weather cools down, not warms up.

Transplant your arugula seedlings outdoors from late December through early February. Before transplanting, harden them off for about a week by gradually exposing them to outdoor conditions. Start with an hour or two of shade, and slowly increase the time and sun exposure each day.

Space your plants about 6 inches apart in well-draining soil. Keep an eye on the weather; even though it's winter, we can still get unexpected temperature swings. Protect your young transplants from frost if necessary.

Direct sowing is the easiest way to grow arugula in Florida. Sow seeds from mid December through early November, aiming for the cooler months. Prepare your soil by loosening it and adding some compost. Arugula prefers well-draining soil with a pH between 6.0 and 7.0.

Sprinkle the seeds lightly over the soil surface and cover them with a thin layer of soil. Keep the soil consistently moist until the seeds germinate, which should take about a week. Thin seedlings to about 6 inches apart. Because arugula bolts in heat, direct sowing in the cooler months ensures the best growth and flavor.

Arugula needs consistent moisture to thrive, but be careful not to overwater, especially with our high humidity. Aim to keep the soil evenly moist, but not soggy. Arugula is not drought-tolerant, so don't let it dry out completely.

During our cooler fall and winter months, you'll likely need to water about once or twice a week, depending on rainfall. Use the "finger test": stick your finger about 2 inches deep into the soil. If it feels dry, it's time to water. Aim for about 1 inch of water per week, including rainfall.

Water at the base of the plants rather than overhead to minimize fungal diseases, which are common in Florida's humid climate. Yellowing leaves can be a sign of overwatering, while wilting leaves indicate underwatering. Arugula's flavor intensifies and it bolts faster if it's too dry. A light layer of mulch can help retain moisture and keep the soil cooler.

You can expect your first harvest of arugula from late to early January, about 40 days after planting. The best time to harvest is when the leaves are young and tender, about 2-3 inches long. At this stage, they have a milder, more delicate flavor.

If you prefer a more peppery taste, let the leaves grow larger, but harvest before the plant starts to flower. To harvest, simply snip off the leaves with scissors or your fingers, leaving the central rosette intact. This allows the plant to continue producing new leaves for several weeks.

To encourage continued production, regularly harvest the outer leaves. As our first frost approaches in late December, keep harvesting to enjoy the last of your arugula before the weather turns too cold. Even a light frost can damage the leaves.

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

Flea Beetles

• What it looks like: Tiny round holes (shot-hole pattern) in the leaves, especially on young seedlings. You might see small, dark beetles jumping when disturbed.
• What causes it: Small jumping beetles that feed on the leaves. They're most damaging to small, young plants.
• How to fix/prevent it: Use row covers to protect seedlings. Delay planting until plants are larger and more resilient. You can also try spraying with neem oil. Interplanting with basil or catnip can help deter them, too.

Bolting in Heat

• What it looks like: The plant sends up a flower stalk, and the leaves become tough and bitter.
• What causes it: Extended warm temperatures. Arugula is a cool-season crop and bolts when temperatures rise.
• How to fix/prevent it: Time your plantings for the cooler months (fall and winter). Provide shade during warm spells. Mulch around the plants to keep the soil cool. Harvest frequently to delay bolting.

Aphids

• What it looks like: Clusters of tiny insects (green, black, or white) on stems and leaf undersides. You might also see sticky honeydew residue or curled and distorted new growth.
• What causes it: Rapidly reproducing sap-sucking insects.
• How to fix/prevent it: Knock them off with a strong spray of water. Encourage ladybugs and lacewings, which are natural predators. Use insecticidal soap or neem oil for heavy infestations.

Downy Mildew

• What it looks like: Yellow patches on the tops of leaves, with fuzzy gray-purple growth on the undersides. Leaves brown and die from the bottom up.
• What causes it: A fungal disease that thrives in cool, humid conditions.
• How to fix/prevent it: Remove affected leaves immediately. Improve air circulation around the plants. Water at the base, never overhead. You can also use a copper-based fungicide as a preventative measure.

Florida Specific Challenges: The combination of hot heat, very-high humidity, and wet-summer rainfall can make growing arugula challenging. The humidity encourages fungal diseases, and the heat causes bolting. Careful watering, good air circulation, and timely planting are key to success.

Arugula benefits from companion planting. Lettuce and spinach are good companions because they have similar growing requirements and don't compete for resources. Carrots and beets are also beneficial, as they help to loosen the soil and improve drainage.

Onions can deter pests like aphids. Avoid planting arugula near strawberries, as they can attract pests that also affect arugula. By choosing the right companions, you can create a thriving and productive garden.