Marigold: Plant Care and Growing Guide

Marigold Basics

• Marigolds are regarded as one of the easiest plants to grow.
• Most varieties bloom reliably from late spring or early summer until hard frost in late fall.
• Marigolds thrive in moderately fertile, dry to moist, well-drained soils. Some light afternoon shade is tolerated in hot summer areas. They are adaptable to poor soils, heat, humidity, and especially drought.
• They work well as bedding plants in mixed borders, as edging plants, in patio containers and some make excellent cut flowers.
• Both African and French Marigolds produce alpha-terthienyl, a substance that suppresses nematodes (microscopic worms that attack the roots of plants), making them suitable for growing in vegetable gardens.
• The flowers attract beneficial insects that not only pollinate but also help control bad bugs. Beneficial insects attracted to the flowers include hoverflies, ladybugs, and parasitic wasps that prey on garden pests.
• Marigolds naturally repel pests such as deer, rabbits, or mosquitoes since they find their odor offensive.
• They are very low-maintenance once established. However, to keep them blooming almost non-stop all summer until frost, they need to be deadheaded.
• Marigolds have no serious pest or disease issues. However, despite their reputation for repelling pests, some insects are attracted to them. Keep an eye out for spider mites, slugs, leafminers, aphids, whiteflies, thrips, and caterpillars.

When to Plant Marigold Flowers?

• The best time to plant French Marigolds and Signet Marigolds is from spring through mid-summer.
• The best time to plant African Marigolds is in the spring after the danger of frost has passed. These flowers need more time to mature and bloom.
• Marigolds can be direct seeded in the garden once soil temperatures reach 65°F (18°C).
• Alternatively, they can be started indoors 6-8 weeks before the last frost date.
• Plants germinate quickly, sprouting within 5-8 days at 70-75°F (21-24°C) and blooming in about 8 weeks.

Where to Plant Marigold Flowers?

• Marigolds are heat-loving plants that thrive in zones 2 to 11.
• They are easily grown in full sun (at least 6 hours of sunlight daily) in moderately fertile, dry to moist, well-drained soils.
• Some light afternoon shade prolongs their blooms in hot summer areas.
• Tall varieties should be planted in locations sheltered from strong winds and heavy rains. These taller varieties may also require some light staking for support.
• Marigolds are adaptable to poor soils, heat, humidity, and especially drought.
• They work well as bedding plants in mixed borders, as edging plants, and in patio containers.
• Thanks to their ability to suppress nematodes, attract bees and beneficial insects, and deter rabbits and deer from nibbling in your garden, they are suitable for growing in vegetable gardens. Marigolds are good companion plants for potatoes, tomatoes, basil, cucumbers, aubergines, squash, melons, asparagus, sweet corn, chilies, and peppers.
• As a mosquito repellent, Marigolds are powerful. Plant them in containers on patios, porches, near entrances or seating areas where you want a mosquito-free zone.
• Surrounding your Marigolds with a succession of flowers will reinforce the beauty of their blooms and extend the season of interest in your landscape. Some of the best companion flowers include Allium, Tickseed (coreopsis), Roses, Sage (Salvia), Bachelor Buttons (Centaurea), Lavender (Lavandula), and Geraniums.

How to Plant Marigold Flowers?

• French Marigolds can easily be started from seed, while African Marigolds are best purchased as young plants (they are slower to mature and can take a long time to bloom).
• Sow seeds 1 inch apart (2.5 cm) and about 1/4 inch deep (1/2 cm) and make sure the seeds are fully covered by the growing media.
• Water thoroughly after planting.
• When the seedlings begin to generate new leaves, thin them. Space French and Signet Marigolds 8-10 inches apart (20-25 cm) and African Marigolds 10-12 inches apart (25-30 cm).
• A general-purpose fertilizer with equal amounts of nitrogen, phosphorus, and potassium should be incorporated into the soil at the time of planting.
• Water well at planting and keep the soil evenly moist for the first couple of weeks until they become established.
• If planting in containers, use a pot that is at least 10 inches across (25 cm) for African and larger French types. Dwarf French Marigolds can grow in a 6-inch container (15 cm). Use any good-quality commercial potting mix, not regular garden soil. Do not crowd potted plants (Marigolds require good air circulation to remain healthy), so be sure to space them properly.
• When planting young plants purchased at a nursery, set your plant in a planting hole at the same depth it was planted in the nursery container. Water well around the plant after planting.
• Plant taller varieties deep: strip off a few of the lower stem leaves and set plants below the remaining leaf scars so as to minimize the need for stem support.
• Spread mulch around the plant to keep moisture in and weeds out.

Caring for Marigold Flowers

Water and Moisture

• Allow the soil to almost dry out between waterings. Water regularly in high heat or dry weather
• Never water Marigolds from overhead as this could lead to powdery mildew issues. Always water at the base of the plant.
• Spread mulch around the plant to keep moisture in and weeds out.
• Once Marigolds have developed a good root system, they will be more drought-tolerant, however, they will produce more blooms if given weekly water.

Fertilizer

• Marigolds do not need any fertilizer unless your soil is extremely poor.
• A general-purpose fertilizer with equal amounts of nitrogen, phosphorus, and potassium should be incorporated into the soil at the time of planting.
• After planting, no extra fertilizer is necessary.
• Too much fertilizer will cause the plant to produce fewer blooms as it devotes its energy to foliage growth.

Deadheading

• Pinching back the early flower buds will help your Marigold to promote more branches and grow bushier. This will prevent the plant from becoming leggy and will encourage more blooms.
• Marigolds do not require deadheading, but if the faded blossoms are removed, this will promote more blooms and extend the flowering season.
• Deadhead faded flowers by pinching off (cutting) the flower head back to the nearest set of leaves.
• Remove rotting flowers and keep the soil surface clean to prevent diseases.

Harvesting

• Marigolds are an excellent choice for fresh bouquets and flower arrangements.
• Harvest stems any time after the blooms are halfway open. Flowers will continue to open and develop thereafter.
• Cut off the central stem almost at ground level, just above 3 to 4 side shoots.
• Remove all foliage below the top set of leaves below the flower. Make the next cuts at the end of the stem being harvested. Place them immediately in water.
• The flowers last 10 to 20 days in a vase. They can also be dried for long-lasting floral arrangements. Strip foliage from perfect blossoms and hang them upside down.

Propagating

• Marigolds are propagated easily from seed.
• At the end of the season, seeds can be saved from open-pollinated cultivars. However, it is best not to save seeds from hybrid cultivars. Their offspring will not look like their parents.

Pest and Diseases

• Marigolds have no serious pest or disease issues. However, some problems may occasionally occur:
• Snails and slugs may eat leaves, especially on young plants. Keep the soil free of leaf debris, and set out slug and snail traps.
• Aphids can be easily treated with horticultural soaps or oils.
• Powdery mildew can be avoided by providing good air circulation between plants and by watering at the base of the plant.