French Marigold in Zone 6B — Pacific Northwest

French Marigolds are a fantastic addition to any Pacific Northwest garden. Their cheerful blooms add a pop of color, their scent can help deter pests, and they're even edible, adding a unique flavor to salads and other dishes. The cool nights and mild summers of our region actually enhance their fragrance, making them even more enjoyable.

While we might struggle with heat-loving plants, French Marigolds thrive with a little planning. Our 162-day growing season gives you plenty of time to enjoy them, whether you start seeds indoors or sow them directly into the garden.

Starting French Marigolds indoors gives you a head start, though it's not strictly necessary in our climate. If you want earlier blooms, start seeds indoors from late March through mid April, about six weeks before you plan to transplant them outside.

Use seed trays with a good seed-starting mix, and provide warmth and light. Bottom watering is a great way to keep the soil evenly moist without damping off. Remember, our springs can be slow to warm up, so indoor starting gives your marigolds a jump on the season.

Transplant your French Marigold seedlings outdoors from mid May through late June, once the danger of frost has passed. Before planting, harden off your seedlings by gradually exposing them to outdoor conditions for about a week.

Space them 8-10 inches apart in a sunny spot. Keep an eye on the weather forecast—we sometimes get unexpected cool snaps even in late spring, so be ready to cover your young plants if needed.

Direct sowing French Marigolds is a simple and reliable method in the Pacific Northwest. Sow seeds directly into the garden from early May through early August, after the soil has warmed up a bit.

Prepare the soil by loosening it and removing any weeds. Plant seeds about ¼ inch deep and space them 8-10 inches apart. Keep the soil consistently moist until the seedlings emerge. Direct sowing is less work, but you'll get blooms a bit later than if you start indoors.

French Marigolds are drought-tolerant once established, making them a great choice for our dry summer months in the Pacific Northwest. During the wet springs, you likely won't need to water them at all unless we have an unusually dry spell.

Once the weather warms up, check the soil moisture regularly using 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, but adjust based on rainfall.

Water at the base of the plants to avoid wetting the foliage, which can encourage fungal diseases. Overwatering can be just as harmful as underwatering, so watch out for yellowing leaves, which can indicate soggy roots. A light layer of mulch can help retain moisture and suppress weeds.

Deadheading is key to keeping your French Marigolds blooming all season long. Simply pinch or cut off the spent flowers just below the flower head.

Do this regularly, as soon as you notice the blooms fading. Toward the end of the season, as the first frost approaches in early October, you can let some of the last flowers go to seed if you want to save them for next year.

You can expect your first harvest of French Marigold blooms from mid June through early October, about 50 days after planting. Harvest the flowers when they are fully open and the petals are vibrant.

To harvest, simply snip the stem just below the flower head. This encourages the plant to produce more blooms. 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.

As the first frost approaches in early October, harvest any remaining flowers. They won't ripen off the vine, but you can enjoy them fresh or dry them for later use.

Here are some common problems you might encounter with French Marigolds in the Pacific Northwest:

Spider Mites

• What it looks like: Fine webbing on the leaves and tiny, pale mites crawling on the undersides. Leaves may appear stippled or bronze.
• What causes it: Hot, dry conditions favor spider mites. Our dry summer months can create the perfect environment for them to thrive.
• How to fix/prevent it: Increase humidity around the plants by misting them with water. Insecticidal soap or neem oil can also be effective.

Powdery Mildew

• What it looks like: White or grayish powdery coating on leaves, stems, and sometimes flower buds. Leaves may curl, yellow, and die.
• What causes it: Powdery mildew is caused by various fungi that thrive 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 properly and pruning. Remove affected leaves. Neem oil or potassium bicarbonate sprays can help. Milk spray (1 part milk to 9 parts water) is surprisingly effective.

Slugs

• What it looks like: Irregular holes in leaves, especially on young plants. Silvery slime trails on and around the plants.
• What causes it: Slugs are prevalent in our wet springs and thrive in damp, shady conditions.
• How to fix/prevent it: Use slug bait, beer traps, or handpick slugs off plants, especially in the evening or after rain. Copper tape around plant containers can also deter them.

Pacific Northwest Specific Challenges: While late blight is a major concern for tomatoes and potatoes in our region, French Marigolds are generally resistant. The mild heat and dry-summer conditions can actually be beneficial for marigolds, as they thrive in these conditions and are less prone to fungal diseases than in more humid climates.

French Marigolds make excellent companion plants in the Pacific Northwest garden. Plant them near tomatoes and peppers to help deter pests like nematodes. Their scent also repels certain insects that can damage basil and cucumbers.

They can also be planted near green beans to deter bean beetles. However, it's worth noting that marigolds can sometimes attract spider mites, which can then spread to your bean plants. So, while generally beneficial, keep an eye out and take action if you see signs of spider mites.