French Marigold in Zone 3B — Great Plains

French Marigolds are worth a spot in your Plains garden for their vibrant color and ability to attract pollinators to your tomatoes and peppers. Plus, they are edible! The mild, peppery taste of the petals can add a unique touch to salads and other dishes. Few things beat the satisfaction of growing your own food and flowers, especially in a place where the growing season feels so fleeting.

Our short 118-day growing season and extreme weather can be challenging, but French Marigolds mature quickly and are surprisingly drought-tolerant. With a little planning, you can enjoy their beauty and benefits from early summer until the first frost.

Starting French Marigolds indoors gives you a head start, but it's not always necessary. If you're itching to garden during those variable spring days, or if you want blooms as early as possible, starting indoors is a good option.

Sow seeds indoors mid-April through early May, about six weeks before you plan to transplant. Use seed trays filled with a good seed-starting mix, keep them warm (around 70-75°F), and provide plenty of light. Bottom watering helps prevent damping off and keeps the seedlings evenly moist.

Be sure to harden off your seedlings gradually by exposing them to increasing amounts of outdoor sunlight and wind over about a week before transplanting. This is especially important in the Plains, where our spring weather can be unpredictable.

Transplant your French Marigold seedlings outdoors from early June through mid-July, after the risk of frost has passed. By this point, even the north of Zone 3B should be safe. Choose a sunny spot with well-drained soil.

Space the plants 8-10 inches apart to allow for good air circulation. Be mindful of our Plains winds – a sheltered location or windbreak can help protect your young transplants. Water them well after planting and keep an eye on them during those first few days, especially if we're experiencing a temperature swing.

Direct sowing French Marigolds is a simple and reliable option, especially if you're not looking for the earliest possible blooms. Wait until the soil has warmed up, generally from mid-May through mid-July.

Prepare the soil by loosening it and removing any weeds or debris. Sow seeds about ¼ inch deep and space them 8-10 inches apart. Keep the soil consistently moist until the seedlings emerge. Direct sowing saves time and effort, but you'll need to be diligent about weeding and protecting the young plants from pests.

French Marigolds are surprisingly drought-tolerant once established, making them a great choice for our variable Plains climate. However, proper watering is still essential, especially during the initial stages of growth.

In spring, water regularly to help seedlings establish strong root systems. Once they're established, reduce watering frequency. During the hot summer months, water deeply but infrequently, allowing the soil to dry out between waterings. A good rule of thumb is to water only when the top two inches of soil feel dry to the touch – the "finger test."

Aim for about one 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 moderate humidity. Signs of underwatering include wilting leaves and stunted growth. Overwatering can lead to root rot, so be sure the soil is well-draining. Mulching around the base of the plants with straw or wood chips helps to retain moisture and suppress weeds, which is especially useful if you get hit by drought.

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, every few days or once a week, to encourage continuous blooming. Towards the end of the season, around the time of our first expected frost in mid- September, you can let some of the flowers dry on the plant to collect seeds for next year's garden.

French Marigolds will start blooming about 50 days after planting, so expect your first harvest from early July through mid-September, depending on when you sowed your seeds. Harvest the flowers when they are fully open and the petals are vibrant.

To harvest, simply snip the flower stem with scissors or pruners. Regular harvesting encourages the plant to produce more blooms, extending the flowering season. As the season winds down and the first frost approaches, you can harvest all remaining flowers to dry and use in crafts or potpourris. Allow some flower heads to dry completely on the plant to collect seeds for next year.

Even though French Marigolds are fairly easy to grow, you might encounter a few problems in our Plains climate. Here's what to watch out for:

Spider Mites

• What it looks like: Fine webbing on the leaves, tiny yellow or brown spots, and overall decline in plant health.
• What causes it: Hot, dry conditions favor spider mites. Our Plains summers can provide just the environment they love.
• How to fix/prevent it: Increase humidity by misting plants regularly. Insecticidal soap or neem oil can help control infestations. Ensure adequate watering to reduce plant stress.

Powdery Mildew

• What it looks like: White or grayish powdery coating on leaves, stems, and sometimes fruit. Leaves curl, yellow, and die.
• What causes it: Powdery mildew thrives in warm days, cool nights, and moderate humidity. Dry leaf surfaces actually favor it.
• 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: Holes in leaves, especially on young plants. Slimy trails on leaves and soil.
• What causes it: Slugs are attracted to moist environments and can be a problem during wet springs.
• How to fix/prevent it: Handpick slugs at night. Use slug bait or traps. Create barriers around plants with copper tape or diatomaceous earth.

Great Plains Specific Challenges: The hot, dry summers in the Great Plains can stress French Marigolds, making them more susceptible to spider mites. Variable rainfall can lead to periods of drought or excessive moisture, so it's important to monitor soil moisture and adjust watering accordingly. Our winds can also damage young plants, so provide wind protection if necessary.

French Marigolds are great companions in the garden, offering benefits to several common Plains crops:

• Tomatoes and Peppers: Marigolds repel nematodes and other soil pests that can harm these plants.
• Basil: Marigolds can deter aphids and other pests that attack basil.
• Cucumbers: Marigolds help repel cucumber beetles, which can transmit diseases.
• Green Beans: While some sources say marigolds are good companions for beans, they can also attract bean beetles. Monitor your plants carefully and remove any pests promptly.