French Marigold in Zone 6B — Southeast

French Marigolds are a worthwhile addition to any Southeast garden. Their bright blooms bring cheerful color, plus they are edible and have a slightly citrusy flavor that can add a unique zest to salads. They also attract pollinators, which is always a plus for our long summer growing season.

While we do have to contend with humidity and disease pressure here, French Marigolds are fairly resilient and with a little attention to timing, you can enjoy them from late spring well into the fall. Our 208-day growing season gives you plenty of time to succession plant and enjoy their benefits.

Starting French Marigold seeds indoors is an option, but honestly, they do so well direct sown that it's often unnecessary unless you're aiming for a very early bloom. If you want to get a jump start, begin in early to late March, about six weeks before you plan to transplant. Use seed trays with a good seed-starting mix, provide warmth (a heat mat helps), and ensure plenty of light, either from a grow light or a very sunny window.

Bottom watering is a good trick for starting seeds. Just set the tray in a shallow dish of water and let the soil soak it up from the bottom, preventing damping off. Our spring can be moderate here, so you'll want to make sure your seedlings have consistent temperatures.

Transplant your French Marigold seedlings outdoors from mid April through late May, once the danger of frost has passed. Before transplanting, harden them off by gradually exposing them to outdoor conditions for about a week. Start with an hour or two of shade, increasing the time and sun exposure each day.

Plant them 8-10 inches apart in a sunny spot with well-drained soil. Keep an eye on the weather forecast – a late cold snap can still happen, even in the Southeast.

Direct sowing French Marigolds is a super easy and effective method for Southeast gardeners. You can sow seeds directly into the garden from early April through late August. The soil should be at least 65°F for optimal germination.

Prepare the soil by loosening it and removing any weeds. Sow seeds 8-10 inches apart, about ¼ inch deep. Keep the soil consistently moist until the seedlings emerge. Direct sowing is convenient, but remember that seedlings will be more vulnerable to slugs and other pests than those started indoors.

French Marigolds are relatively drought-tolerant once they're established, which is great for our hot summers. However, they still need consistent watering, especially when young. Aim to provide about 1 inch of water per week, either from rainfall or irrigation.

The "finger test" is your friend: stick your finger about 2 inches deep into the soil. If it feels dry, it's time to water. Water at the base of the plants, avoiding overhead watering as much as possible. Our humid climate makes fungal diseases more likely, and wet foliage only encourages them.

In the spring, you might need to water a couple of times a week if it's dry. During our wet-summer months, you might not need to water at all unless we're experiencing a dry spell. Signs of underwatering include wilting leaves and dry, cracked soil. Overwatering can lead to yellowing leaves and root rot. A layer of mulch around the base of the plants helps retain moisture and suppress weeds, which is essential for our clay soil.

Deadheading is key to keeping your French Marigolds blooming all season long. Regularly remove spent flowers by pinching or cutting them off just below the flower head. This encourages the plant to produce more blooms instead of putting energy into seed production.

You can deadhead throughout the growing season, from late spring until the first frost. As late October approaches and our first frost looms, you can let the last few flowers go to seed if you want to collect them for next year.

You can expect your first harvest of French Marigold blooms about 50 days after planting, meaning late May through late October if you succession plant. Harvest the flowers when they are fully open and the color is vibrant. To harvest, simply cut the stem just below the flower head.

Regular harvesting encourages continuous production. If you want to save seeds, allow some of the flower heads to dry completely on the plant. Once dry, you can easily collect the seeds for planting next year. Even as our first frost approaches in late October, you can often extend the harvest by covering the plants on cold nights.

Here are a few common problems you might encounter with French Marigolds in the Southeast:

Spider Mites

• What it looks like: Fine webbing on the leaves and stems, tiny yellow or brown spots on the leaves, and overall plant weakness.
• What causes it: Spider mites thrive in hot, dry conditions. While we have humidity, sometimes we have periods of dry heat, especially late in the summer.
• How to fix/prevent it: Increase humidity around the plants by misting them with water. Insecticidal soap or neem oil can also be effective. Ensure good air circulation to deter them.

Powdery Mildew

• What it looks like: White or grayish powdery coating on leaves, stems, and sometimes buds. Leaves curl, yellow, and die.
• What causes it: Powdery mildew is a fungal disease that thrives in warm days, cool nights, and moderate humidity. Dry leaf surfaces actually favor it.
• How to fix/prevent it: Improve air circulation by spacing plants adequately and pruning if necessary. Remove affected leaves promptly. Neem oil or potassium bicarbonate sprays can help. A milk spray (1 part milk to 9 parts water) is surprisingly effective.

Slugs

• What it looks like: Holes in the leaves, especially on young plants. Slimy trails on the leaves and surrounding soil.
• What causes it: Slugs are attracted to moist environments and can be a problem, especially during our wet spring.
• How to fix/prevent it: Handpick slugs at night. Use slug bait or diatomaceous earth around the plants. Encourage natural predators like birds and toads.

Southeast Specific Challenges: The hot, humid summers in the Southeast create ideal conditions for fungal diseases like powdery mildew. Our wet-summer rainfall can also contribute to slug problems. Be vigilant about monitoring your plants and take action quickly to prevent problems from getting out of hand.

French Marigolds are excellent companion plants for several vegetables in the Southeast garden. Plant them near tomatoes, peppers, and basil, as their scent repels many common pests like nematodes and whiteflies, which can be a real nuisance in our long growing season. They also work well with cucumbers, helping to deter cucumber beetles.

Avoid planting French Marigolds near beans. While marigolds generally have pest-repelling properties, they can sometimes inhibit the growth of beans.