How to Grow French Marigolds Like a Pro Gardener

French marigolds, Tagetes patula, are popular annuals featuring double, semi-double or crested ray flowers in reds, oranges, yellows, and mixed colors with a long bloom season from early summer through frost. They exhibit a bushy growth habit with 1- to 3-inch flowers opening above strongly scented, fern-like foliage on 6- to 12-inch stems.

This diminutive plant is a workhorse with multiple uses and grows equally well in containers and in the garden. Foliage can cause skin irritation in sensitive individuals.

These are low-maintenance annuals easily grown from seed and readily available at garden centers and nurseries. Use this guide to learn about French marigolds and ways to add them to your garden.

French Marigold Care

French marigolds are one of the easiest annuals to grow and care for starting with saved seed, purchased seed, or nursery seedlings.

How to Plant French Marigold

Plant nursery seedlings 10 to 12 inches apart for mass plantings and borders. Water well until plants are established and then allow soil to dry between waterings. Loosen heavy clay soils by working aged compost or sand into the bed before transplanting. In poor soil add a balanced fertilizer at planting time such as an NPK 10-10-10.

Seeds can be directly sown or started indoors six to eight weeks before the final frost in your area. Sow seeds 1 inch apart and 1/4 inch deep covering them completely with soil. Water thoroughly. Thin seedlings to 10 to 12 inches apart once foliage appears.

Tip

French marigolds repel nematodes and attract beneficial insects working as efficient companion plants for tomatoes and other vegetables.

Where to Plant French Marigold

French marigolds adapt to heat, poor soil, humidity, and drought. Choose a location that receives full sun, at least six hours daily. In areas with hot summers, they tolerate some afternoon shade.

Dwarf varieties can be planted in 6-inch pots. Plant regular varieties in 12-inch pots and tall hybrids in areas sheltered from strong winds.

When to Plant French Marigold

These are heat-loving annuals so wait to plant out or direct sow seeds until all danger of frost has passed in your growing zone. In cooler climates, French marigolds are mostly planted out in spring for summer-long blooms.

In warmer climates, some varieties are successfully planted for autumn color with flowers opening as temperatures drop. Set out autumn blooming types from late August through early September.

Light

French marigolds thrive in full sun, at least six hours daily. They will grow in some shade as long as they receive a minimum two hours of direct exposure. Too much shade leads to fewer flowers and a shorter bloom period.

Soil

Highly tolerant of poor soils, these annuals nevertheless put on a better show when grown in at least moderately fertile soil. The single most important requirement is that the soil drains well.

Water

Water seeds and seedlings well when planting out and keep soil moderately moist for the first several weeks until plants establish a strong root system. French marigolds favor dry conditions and are drought tolerant, however, flowering improves with regular weekly irrigation, allowing the soil to dry out almost completely between waterings.

Water at soil level to prevent fungal diseases like powdery mildew. Add mulch to retain moisture and deter weeds. Potted plants require a regular watering schedule.

Temperature and Humidity

Best flowering occurs at temperatures between 68°F and 75°F. French marigolds are not frost-hardy but will continue to grow at temperatures as low as 40°F with reduced flowering. They adapt to a wide range of humidity levels.

Types of French Marigold

French marigolds come in numerous varieties, enough to suit any purpose in the landscape.

• T. patula 'Bonanza': Double-crested 2- to 3-inch flowers on plants 10 to 12 inches tall. Five color combinations in yellow, orange, and maroon.

• T. patula 'Boy O' Boy': Dwarf 6-inch tall plants featuring profuse flowers in maroon, yellow and orange.

• T:. patula 'Hero': Double carnation flowers 2 inches across in seven color combinations of yellow, orange and maroon. Plants grow to 10 inches tall.

• T. patula 'Hot Pak': Small 7-inch plants extremely tolerant of heat and humidity with crested flowers in yellow, red, orange, and mixed.

• T. patula 'Janie': Double carnation flowers in six combinations of yellow, orange, and maroon. At 8 inches tall, this early bloomer is ideal for container growing. Disease resistant.

Pruning

Begin by pinching off early buds to encourage branching. Trim leggy growth to a more pleasing shape by cutting back stems to just above a set of leaves using a fine scissor-like snipper.

Avoid removing more than one-third of the plant during any single pruning. Deadhead spent flowers to keep plants in bloom.

How to Grow French Marigold From Seed

Growing French marigolds from seed is easy with reliable, rapid germination followed by flowers in just six to eight weeks. It's a gardening project well-suited for children.

Large seeds are easy to handle and can be directly sown in the garden or started indoors in flats. Wait until all danger of frost has passed and soil temperature reaches 70°F to 75°F before planting seed outdoors then follow these steps:

Plant Seeds For a Border

1. Sow seeds 1/4 inch deep and 1 inch apart.

2. Cover completely with soil.

3. Keep soil evenly moist but not soggy.

4. Thin to 10- to 12-inches apart once foliage emerges.

Plant Seeds For Groupings

1. Plant four seeds 1/4 inch deep and 1 inch apart in a small square.

2. Measure 10 to 12 inches horizontally, vertically and diagonally to create a larger square planting four seeds in each corner.

3. Water thoroughly and maintain soil moisture.

4. Once seedlings emerge, thin plants to one in each corner.

Start Seeds Indoors

Start seeds indoors six to eight weeks before final frost for earlier blooms. To grow your own transplants, you'll need a seed starting tray, flat, or small pot, plastic dome or covering, potting mix, and water. Follow these steps:

1. Fill a container with loose, well-draining potting mix. Fine, sifted compost, seed starting mix, and potting soil all work for germinating French marigold seeds.

2. Moisten the potting mix and sow seeds about 1/4 inch deep and 1 inch apart.

3. Cover the container with plastic and place in a warm sunny location with consistent temperatures between 70°F and 75°F.

4. Keep soil evenly moist but not soggy and do not allow it to dry out.

5. Remove plastic when top growth emerges in seven to 14 days.

6. Thin seedlings or transplant into individual cells or small pots once they are sturdy enough to handle and 2 to 3 inches tall with several sets of leaves.

7. Harden off before transplanting outdoors into containers or directly into the garden.

Tip

Some gardeners recommend planting French marigold seeds by pushing the pointed black end into the soil. Seeds laid flat and covered with soil or planted with the feathery end down also germinate reliably.

Potting and Repotting French Marigold

French marigold varieties typically stay between 6 and 12 inches tall. Start with the right-sized container and avoid having to thin, transplant, or otherwise remove and discard plants due to overcrowding. A 6-inch pot will accommodate two or three 6- to 8-inch tall plants. For taller plants, choose a 12-inch container for groupings and space plants evenly.

Common Pests and Plant Diseases

French marigolds stand up exceedingly well to pests and plant diseases with some varieties developed to withstand less than ideal environments. Here are a few issues that may arise.

Spider mites and thrips damage foliage and weaken plants. If caught early, they can sometimes be knocked down with a strong spray from your garden hose. Use neem or horticultural oil if you encounter an infestation.

Dense foliage is prone to fungal and leaf spot diseases including powdery mildew, botrytis, and leaf spots. Adhere to recommended spacing to allow plenty of air circulation and water at ground level to avoid wet foliage.

How to Get French Marigold to Bloom

Bloom Months

Flowers begin to bud and open when temperatures reach 70°F, usually starting in early summer and continuing until the first frost in autumn. In frost-free climates plants eventually decline with age.

How Long Does French Marigold Bloom?

Each flower stays vibrant for three to four weeks before petals fade and dry out. Consistent deadheading allows new blooms to form.

What Do French Marigold Flowers Look and Smell Like?

French marigold flowers add a splash of deep, rich maroon-red, orange, and yellow. They come in doubles, semi-doubles, and crested ray flowers with a decorative ruffled appearance.

The fragrance of French marigolds is described as warm, bitter, acidic, musky, or sharp depending on who you ask.

How to Encourage More Blooms

Keep these annuals flowering with consistent deadheading. Pinch out early buds to encourage more branching which translates to more flowers. If soil is extremely poor or clay-like consider adding a balanced NPK 10-10-10 fertilizer at planting time.

Deadheading French Marigold Flowers

Pinch off spent blooms above the set of leaves just below the base of the seed pod.

Common Problems With French Marigold

Spots on Leaves

Usually attributed to overly wet foliage, circular or irregular tan to brown spots develop and enlarge as the disease spreads. Fungicides are most effective as a preventive applied in early spring as soon as leaves develop. Water early to allow foliage to dry before nightfall and remove damaged leaves.

Root Rot

Wilting of the entire plant can be an indication of root rot and is usually the result of inadequate drainage, overwatering, or poor air circulation. Take steps early to correct these problems. Damaged roots quickly become irreparable and plants have to be discarded.

Scorched Leaves

Leaf scorch affects weak, stressed plants causing browning and drying along leaf tips and margins. The problem is often traced to mineral deficits in the soil. Have soil tested before planting to check for a neutral pH level and determine if amendments are needed.

Wilted Leaves

Wilt can set in at any stage of growth, starting with lower leaves and often initially affecting only one side of the plant. Chemical controls are not available for vascular wilts like fusarium or verticillium so prevention is key. Avoid planting in infected soil and choose resistant varieties.

Frequently Asked Questions

Do French marigolds come back every year?

French marigolds are grown as annuals and complete their life cycle in one year. They may reseed but plants are either killed by frost or die back with age.

What is the difference between French marigolds and African marigolds??

French marigolds (T. patula) and African marigold (T. erecta) are two different species. French marigolds are compact with 1- to 3-inch flowers. African marigolds are taller, growing 24 to 36 inches tall with larger 4-inch flowers. Colors are similar however African marigolds also produce a white bloom.

What garden pests do French marigolds repel?

Studies have proven French marigolds are an effective deterrent to root knot nematodes. Claims they repel other garden pests are largely anecdotal although the pungent foliage may put off some animal and insect pests such as mosquitos. Flowers attract beneficial insects that help control pests like hornworms, aphids, and white fly.

20 Types of Marigolds You Should Be Growing to Keep Pests Away

Read the original article on The Spruce.