Arugula in Zone 9A — Florida

Arugula, with its peppery bite, is a fantastic addition to any Florida garden. It's incredibly versatile – toss it in salads, use it as a pizza topping, or even blend it into pesto. The satisfaction of harvesting fresh greens throughout our mild winters is something every Florida gardener can appreciate.

Our Florida gardening calendar is different, and while our summers are the slow season, arugula thrives in the cooler months. We do have to be mindful of the heat and humidity, but with proper timing and care, you can enjoy a steady supply of this flavorful green during our extended 327-day growing season.

Starting arugula indoors is an option, but honestly, direct sowing is usually easier here in Florida. If you want a head start, especially for that early winter harvest, you can start seeds indoors from late December through mid January, about 3 weeks before you plan to transplant.

Use seed trays with a good seed-starting mix and keep them in a warm, well-lit area. Bottom watering is a great way to keep the soil consistently moist without overwatering, which is especially important in our humid climate. Remember, our spring is reversed; we're trying to get a jump on the cool season, not extend the warm one.

Transplant your arugula seedlings outdoors from mid January through early March. Before transplanting, harden them off by gradually exposing them to outdoor conditions for about a week. This helps them adjust to the Florida sun and wind.

Space the seedlings about 6 inches apart in well-drained soil. Keep an eye on the weather forecast; a late cold snap can happen, so be ready to cover your seedlings if necessary.

Direct sowing arugula is the most common and easiest method for Florida gardeners. You can direct sow from early January through early November, taking advantage of our long growing season. The trick is to avoid the hottest part of the year, as arugula bolts quickly in the heat.

Prepare your soil by loosening it and adding compost. Arugula prefers soil temperatures between 45°F and 65°F for optimal germination. Sow seeds about ¼ inch deep and 6 inches apart.

Arugula needs consistent moisture, but it doesn't like to be waterlogged, which is a fine line to walk with our Florida humidity. During our typically drier fall and winter months, aim for about 1 inch of water per week. In the spring, you might need to increase that slightly as temperatures rise.

Stick your finger about 2 inches into the soil to check moisture levels. If it feels dry, it's time to water. Water at the base of the plants to avoid getting the leaves wet, which can encourage fungal diseases in our humid environment. Overhead watering is best avoided.

Underwatering will cause the leaves to become more intensely peppery and can stress the plants. Overwatering, on the other hand, can lead to root rot. A light layer of pine straw mulch can help retain moisture and suppress weeds, common issues in Florida gardens.

During our wet-summer, you may not need to water at all, unless there are dry spells.

You can expect your first arugula harvest about 40 days after planting, which means if you plant in late January, you'll be enjoying fresh greens by mid February. Look for leaves that are about 2-3 inches long for a milder flavor. Larger leaves will have a more pronounced peppery taste.

Harvest by snipping off the outer leaves, leaving the inner leaves to continue growing. This cut-and-come-again method will give you a continuous harvest for several weeks.

As late December approaches and our first frost threatens, harvest any remaining arugula. It can tolerate a light frost, but prolonged freezing temperatures will 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 leaves. You'll see small, dark beetles that jump when disturbed. Worst damage is to young seedlings.
• What causes it: These are small jumping beetles that feed on leaves. They are most damaging to small, young plants.
• How to fix/prevent it: Use row covers to protect seedlings during their vulnerable stage. Delay planting until plants are larger. You can also try a kaolin clay coating or neem oil spray. Interplanting with basil or catnip can also help. Healthy, vigorous plants often outgrow the damage.

Bolting in Heat

• What it looks like: The plant sends up a flower stalk, and the leaves become tough and bitter. Harvest quality declines quickly.
• What causes it: Extended warm temperatures cause arugula to bolt.
• How to fix/prevent it: Time your plantings for cool weather (spring/fall). Choose bolt-resistant varieties. Provide shade during warm spells. Mulch to keep the soil cool. Harvest frequently before bolting progresses too far.

Aphids

• What it looks like: Clusters of tiny soft-bodied insects (green, black, or white) on stems and leaf undersides. You'll also see sticky honeydew residue and curled or distorted new growth.
• What causes it: These are rapid-reproducing sap-sucking insects. Populations explode in warm weather.
• How to fix/prevent it: A strong water spray can knock them off. Encourage ladybugs and lacewings, which are natural predators. Use insecticidal soap for heavy infestations. Neem oil also works systemically. Avoid excess nitrogen fertilizer, as it attracts them.

Downy Mildew

• What it looks like: Yellow patches on leaf tops with fuzzy gray-purple growth on undersides. Leaves brown and die from the bottom up.
• What causes it: This is an oomycete pathogen that spreads in cool, humid conditions via wind-carried spores.
• How to fix/prevent it: Remove affected leaves immediately. Improve air circulation. Water at the base, never overhead. Copper-based fungicides can be used for prevention. Plant resistant varieties where available.

Florida Specific Challenges: Our hot heat, very-high humidity, and wet-summer rainfall create a perfect storm for fungal diseases and can stress arugula, causing it to bolt prematurely. Careful attention to watering and air circulation is key.

Arugula benefits from companion planting. Lettuce and spinach make good companions because they have similar growing requirements and help to fill space, suppressing weeds. Carrots and beets loosen the soil, which benefits arugula's root system. Onions deter pests. Avoid planting arugula near strawberries, as they can attract pests that also affect arugula.