French Marigold in Zone 7B — Pacific Northwest

French Marigolds are a fantastic addition to any Pacific Northwest garden. Their bright, cheerful blooms add a pop of color to your veggie beds, and their fragrance can help deter pests. Plus, they're edible! The slightly citrusy, spicy flavor of the petals makes a unique garnish for salads and other dishes.

While our mild summers and wet springs can present some challenges, French Marigolds are surprisingly adaptable. With a 193-day growing season, you'll have plenty of time to enjoy their beauty and benefits. Careful timing is key, but you can definitely grow these successfully in our PNW climate.

Starting French Marigolds indoors isn't strictly necessary in our region, but it can give you a head start, especially if we're having a particularly cool spring. Aim to sow seeds mid-March through early April, about six weeks before you plan to transplant them outside.

Use seed trays filled with a good seed-starting mix. Keep them warm – a heat mat helps – and provide plenty of light, either from a sunny windowsill or a grow light. Water from the bottom by setting the tray in a shallow container of water until the soil surface is moist. This encourages strong root growth and avoids damping off, which can be a problem during our overcast spring days.

Transplant your French Marigold seedlings outdoors late April through early June, after the danger of frost has passed. Before planting them in their final spot, be sure to harden them off. This means gradually exposing them to outdoor conditions for about a week, starting with just an hour or two of sunlight and increasing the time each day.

Plant them 8-10 inches apart in a sunny spot. Keep an eye on the weather forecast, as we can still get some unexpected cold snaps. If a late frost is predicted, cover your young plants with a frost blanket or cloche.

Direct sowing French Marigolds is a simple and effective method in our climate, especially since our soil warms up gradually. Sow seeds mid April through late August for a succession of blooms.

Choose a sunny spot with well-drained soil. Lightly rake the soil surface and sow seeds about ¼ inch deep, spacing them 8-10 inches apart. Keep the soil consistently moist until the seedlings emerge. Direct sowing is a great option for later plantings when the soil has warmed up sufficiently.

French Marigolds are fairly drought-tolerant once established, which is a real plus during our dry summer months. While they don't need a ton of water, consistent moisture is important, especially when they're young.

During the wet springs, you probably won't need to water them much at all, unless we're experiencing an unusually dry spell. Once summer arrives, check the soil moisture regularly. 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, either from rainfall or irrigation.

Water at the base of the plants to avoid wetting the foliage, as this can encourage fungal diseases. While our summers are dry, overhead watering can still lead to problems. Signs of underwatering include wilting leaves and dry, crispy edges. Overwatering can lead to yellowing leaves and root rot. A layer of mulch around the base of your plants will 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, where you see a new bud forming.

You can deadhead them throughout the growing season, from early June through late October. As the first frost approaches in late October, you can let the last few flowers go to seed if you want to collect them for next year. Otherwise, clear the plants from your garden beds after they've been hit by frost.

You can expect your first harvest of French Marigold flowers around early June, about 50 days after planting. The flowers are ready to harvest when they are fully open and the petals are vibrant.

To harvest, simply snip the flower head off with scissors or pruners. Be careful not to damage the surrounding foliage. Harvesting flowers regularly will encourage the plant to produce even more blooms. Even as we approach our first frost in late October, French Marigolds can still provide a final burst of color.

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, spider-like mites on the undersides. Leaves may appear stippled or yellowed.
• What causes it: Dry, hot 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 regularly. You can also try spraying them with a strong jet of water to dislodge the mites. Insecticidal soap or neem oil can be effective treatments.

Powdery Mildew

• What it looks like: White or grayish powdery coating on leaves, stems, and sometimes fruit. Leaves curl, yellow, and die. Reduces plant vigor.
• What causes it: Various fungi that thrive in warm days, cool nights, and moderate humidity. Dry leaf surfaces actually favor it (unlike most fungi).
• How to fix/prevent it: Improve air circulation through spacing and pruning. Remove affected leaves. Neem oil or potassium bicarbonate sprays help. Milk spray (1 part milk to 9 parts water) is surprisingly effective. Plant resistant varieties.

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 thrive in our wet springs and mild, damp conditions. They're especially fond of tender seedlings.
• How to fix/prevent it: Use slug bait, beer traps, or copper tape to deter slugs. Handpicking them in the evening or early morning can also be effective.

Pacific Northwest Specific Challenges: While French Marigolds are relatively easy to grow, our mild heat and dry-summer humidity can sometimes create challenges. The dry summers can lead to spider mites, while our cool, wet springs can attract slugs. However, with a little attention and proactive measures, you can overcome these challenges and enjoy a bountiful harvest of beautiful blooms.

French Marigolds are excellent companion plants for several vegetables in the Pacific Northwest garden. They are known to deter certain pests, making them a valuable addition to your veggie patch.

• Tomato, Pepper, Basil: Marigolds repel nematodes and other soil pests that can damage tomato and pepper plants. Basil also benefits from this pairing.
• Cucumber: Marigolds help deter cucumber beetles, which can transmit diseases to cucumber plants.
• Beans-green: Marigolds deter Mexican bean beetles, which can cause significant damage to bean plants.

Avoid planting French Marigolds directly next to beans-green, as they can sometimes attract spider mites, which can then spread to the beans.