Arugula in Zone 7B — Mid-Atlantic

Arugula, with its peppery bite, is a fantastic addition to any Mid-Atlantic garden. It thrives in our four seasons, providing fresh greens in spring and fall when other crops are just getting started or winding down. You can easily add it to salads, pizzas, or even pesto for a unique twist.

Our humid summers and occasional variable spring weather can present challenges, but with careful timing, you can enjoy a steady supply of arugula throughout much of our 214-day growing season. Don't let the potential for bolting intimidate you!

Starting arugula indoors in the Mid-Atlantic is certainly possible, but it's often not necessary. Given our moderate spring and long growing season, direct sowing usually works just fine. However, if you're eager to get a very early start or want to ensure a continuous supply, starting seeds indoors from mid-February through mid-March (about 3 weeks before transplanting) can give you a head start.

Use seed trays with a good seed-starting mix, and keep them in a warm location with plenty of light – a sunny windowsill or under grow lights works well. Bottom watering helps prevent damping-off, which can be a problem in our humid climate.

Transplant your arugula seedlings outdoors from mid-March through late April, once the soil has warmed up a bit and the risk of hard frost has passed. Before transplanting, 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 plants about 6 inches apart to allow for good air circulation. Keep an eye on the weather forecast, as we can still get unexpected cold snaps during this time. Covering your transplants with row covers can protect them from any late frosts.

Direct sowing arugula is the easiest and most common method for Mid-Atlantic gardeners. You can sow seeds directly into the garden from early March through early September, giving you multiple harvests throughout the growing season.

Prepare the soil by loosening it and adding some compost. Arugula prefers well-drained soil. Sow seeds about ¼ inch deep and 6 inches apart. Keep the soil consistently moist, especially during germination. Remember that arugula bolts in the heat, so focus on planting in the cooler parts of the year for the best results.

Arugula needs consistent moisture to thrive in our Mid-Atlantic climate. While we benefit from even rainfall, our humid summers can also lead to rapid evaporation, so regular watering is key. Aim to keep the soil consistently moist, but not waterlogged.

During the spring and fall, when temperatures are cooler, you might only need to water once or twice a week, depending on rainfall. In the heat of summer, you may need to water daily, especially if the plants are in full sun. Stick your finger about 2 inches deep into the soil to check the moisture level – if it feels dry, it's time to water. Generally, aim for about 1 inch of water per week, either from rainfall or irrigation.

Water at the base of the plants to avoid wetting the foliage, which can encourage fungal diseases in our humid environment. Mulching around the plants with straw or shredded leaves helps to retain moisture and suppress weeds. Wilting leaves indicate underwatering, while yellowing leaves can indicate overwatering. Adjust your watering schedule accordingly.

You can expect your first arugula harvest in the Mid-Atlantic around mid-April if you started early, and harvest can continue through early November with successive plantings. Arugula is ready to harvest about 40 days after planting.

Harvest the leaves when they are 2-3 inches long for a milder flavor, or let them grow larger for a more peppery taste. Simply snip off the outer leaves with scissors or a knife, leaving the inner leaves to continue growing. This encourages continuous production.

To extend the harvest into the fall, plant another crop in early September. As the first frost approaches in early November, consider covering your arugula with a cold frame or row cover to protect it from the cold and extend the harvest even further.

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 love to feed on arugula leaves. They're most active in warm, dry weather, and can be especially problematic for young plants.
• How to fix/prevent it: Use row covers to protect seedlings during their vulnerable stage. Delay planting until plants are larger and more resilient. You can also try spraying with kaolin clay or neem oil. Interplanting with basil or catnip can help deter them.

Bolting in Heat

• What it looks like: The plant sends up a flower stalk prematurely. The leaves become tough and bitter, making them less palatable.
• What causes it: Arugula is a cool-season crop and bolts (goes to seed) when temperatures rise consistently above 80°F. This is a common issue during our humid summers.
• How to fix/prevent it: Time your plantings for cooler weather in spring and fall. Choose bolt-resistant varieties. Provide shade during warm spells with shade cloth. Mulch to keep the soil cool. Harvest leaves frequently to delay bolting.

Aphids

• What it looks like: Clusters of tiny soft-bodied insects (green, black, or white) on stems and leaf undersides. You might also notice a sticky honeydew residue and curled or distorted new growth.
• What causes it: Aphids are sap-sucking insects that thrive in warm weather. They can reproduce rapidly, especially when conditions are favorable.
• How to fix/prevent it: Knock them off with a strong spray of water. Encourage natural predators like ladybugs and lacewings. For heavy infestations, use insecticidal soap or neem oil. Avoid over-fertilizing with nitrogen, as this can attract aphids.

Downy Mildew

• What it looks like: Yellow patches on leaf tops with fuzzy gray-purple growth on undersides. Leaves will eventually brown and die from the bottom up.
• What causes it: This fungal disease spreads in cool, humid conditions via wind-carried spores. Our Mid-Atlantic springs and falls can be particularly susceptible.
• How to fix/prevent it: Remove affected leaves immediately. Improve air circulation by spacing plants properly. Water at the base of the plants, avoiding overhead watering. Consider using copper-based fungicides as a preventative measure. Plant resistant varieties if available.

Mid-Atlantic Specific Challenges: The combination of moderate-to-hot summers and humid conditions in the Mid-Atlantic makes arugula particularly susceptible to bolting and fungal diseases. Consistent monitoring, proper watering techniques, and timely harvesting are essential for success.

Companion planting can help your arugula thrive in the Mid-Atlantic garden.

Good companions for arugula include lettuce and spinach. They share similar growing requirements and won't compete for resources. Carrots and beets are also good choices, as they help loosen the soil and improve drainage. Onions can deter some pests, providing added protection for your arugula.

Avoid planting arugula near strawberries. Strawberries can attract pests that also affect arugula, increasing the risk of infestation.