Arugula in Zone 6B — Mid-Atlantic

Arugula is a fantastic addition to any Mid-Atlantic garden. Its peppery bite adds a delicious kick to salads, pizzas, and pesto. Plus, it's a fast grower, giving you a quick and satisfying harvest in our four seasons.

While our humid summers can present challenges, careful timing lets you enjoy arugula in both spring and fall. Our 198-day growing season gives you plenty of opportunities to plant and harvest this tasty green.

Starting arugula indoors is an option, but honestly, it's usually not necessary here in the Mid-Atlantic. Since our springs are moderate and arugula germinates quickly, direct sowing is often the easiest route. However, if you want a head start, or we're having a particularly cool spring, starting seeds indoors from late February through mid March is perfectly fine.

Use seed trays or small pots filled with a good seed-starting mix. Keep the soil consistently moist by watering from the bottom to prevent damping off. Place the trays under grow lights or in a very sunny window until seedlings are ready to transplant.

Transplant your arugula seedlings outdoors from late March through early May, once the danger of any hard frost has passed. Before planting, harden off your seedlings by gradually exposing them to outdoor conditions for about a week. This helps them adjust to the sun and wind.

Space the seedlings about 6 inches apart in well-drained soil. Watch out for unexpected cold snaps that are possible this time of year. Row covers can provide extra protection if needed.

Direct sowing arugula is easy and effective in the Mid-Atlantic. You can sow seeds directly into the garden from mid March through early September. Arugula is quick to germinate, so you'll see seedlings popping up in no time.

Choose a spot with full sun to partial shade, especially for summer plantings. Prepare the soil by loosening it and removing any rocks or debris. Sow seeds about ¼ inch deep and 6 inches apart. Keep the soil consistently moist, and you'll be harvesting in just a few weeks. Be aware that arugula bolts quickly in the heat, so focus on spring and fall plantings.

Arugula needs consistent moisture to thrive, especially during our humid Mid-Atlantic summers. Aim to keep the soil evenly moist, but not waterlogged. The "finger test" is a good way to check: stick your finger about 2 inches into the soil. If it feels dry, it's time to water.

Typically, arugula needs about 1 inch of water per week, either from rainfall or irrigation. During hotter periods, you might need to water more frequently. Water at the base of the plants to avoid wetting the leaves, which can encourage fungal diseases in our humid climate.

Signs of underwatering include wilting leaves and slow growth. Overwatering, on the other hand, can lead to yellowing leaves and root rot. Applying a layer of mulch, such as straw or shredded leaves, helps retain moisture and suppress weeds.

You can expect your first arugula harvest in late April if you planted early, and all the way through early November, depending on your planting schedule. Arugula is ready to harvest about 40 days after planting. Look for leaves that are 2-3 inches long for a milder flavor, or let them grow larger for a more peppery taste.

Harvest by snipping off the outer leaves with scissors, leaving the inner leaves to continue growing. This cut-and-come-again method encourages continuous production throughout the season. Be sure to harvest before the plants start to flower, as the leaves will become bitter once bolting begins.

As our first frost approaches in late October, harvest any remaining leaves. Arugula can tolerate a light frost, but prolonged freezing temperatures will damage the plants.

Here are some common problems you might encounter growing arugula in the Mid-Atlantic:

Flea Beetles

• What it looks like: Tiny round holes (shot-hole pattern) in leaves, especially on young seedlings. You might see small dark beetles jumping when disturbed.
• What causes it: These small jumping beetles feed on the leaves, causing significant damage to small plants. They are prevalent in the spring when other food sources are scarce.
• How to fix/prevent it: Use row covers to protect seedlings during their vulnerable stage. Delay planting until plants are larger and more resilient. Coating plants with kaolin clay can deter beetles. Neem oil spray can help control infestations. Interplanting with basil or catnip may also help.

Bolting in Heat

• What it looks like: The plant sends up a flower stalk, and the leaves become tough and bitter.
• What causes it: Arugula is a cool-season crop, and it bolts (goes to seed) when temperatures rise. This is especially common during our humid summers.
• How to fix/prevent it: Time your plantings for cool weather in spring and fall. Choose bolt-resistant varieties. Provide shade during warm spells with shade cloth. Mulch to keep the soil cool. Harvest frequently to delay bolting.

Aphids

• What it looks like: Clusters of tiny soft-bodied insects (green, black, or white) on stems and leaf undersides. Sticky honeydew residue. Curled or distorted new growth.
• What causes it: These sap-sucking insects reproduce rapidly, especially in warm weather. Ant colonies may farm them for the honeydew they produce.
• How to fix/prevent it: Knock them off with a strong water spray. Encourage natural predators like ladybugs and lacewings. Apply insecticidal soap for heavy infestations. Neem oil works systemically. Avoid excess nitrogen fertilizer, which attracts aphids.

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 oomycete pathogen spreads in cool, humid conditions via wind-carried spores. It thrives in our region's humidity.
• How to fix/prevent it: Remove affected leaves immediately. Improve air circulation by spacing plants properly. Water at the base, never overhead. Use copper-based fungicides for prevention. Plant resistant varieties where available.

Mid-Atlantic Specific Challenges: Our region's combination of moderate-to-hot summers and high humidity creates an environment where bolting and fungal diseases like downy mildew can be significant problems for arugula. Careful attention to watering, planting times, and variety selection is key to success.

Arugula benefits from companion planting. Lettuce and spinach make good companions because they share similar growing requirements and don't compete for nutrients. Carrots and beets loosen the soil, making it easier for arugula roots to grow, while onions deter pests like aphids.

Avoid planting arugula near strawberries. Strawberries prefer acidic soil, while arugula prefers a more neutral pH. Planting them together can negatively impact the growth of both plants.