Marigolds are one of the most dependable and durable annual flowers that you can plant in your garden. They are easy to start from seed and there are few pests or disease that bother them. In addition, marigolds are not fussy about the soil and work well planted in the ground or in containers. I cannot remember a year when we did not have marigolds in our garden. This post contains guidance for growing and caring for marigolds.
Marigolds can be classified as follows with French and African being the most common:
- French (Tagetes patula) – Dwarf, bushier plants with both solid and multi-colored flowers. Long blooming season from spring up to the first frost.
- African (Tagetes erecta) – Tall plants with pom-pom double flowers in yellow and orange. Also referred to as American marigolds.
- Triploid is a cross between the French and African marigold.
- Signet (Tagetes tenuifolia) – Bushy plants with fine lacey foliage and single flowers. Signet marigolds are edible.
The plants range in height from 6 inches (dwarf French variety) to 3’ (African variety). The flower petals range in size from 2 inches across to up to 5 inches.
Love is the flower you’ve got to let grow.
John Lennon
Mounding French Marigolds
SCIENTIFIC CLASSIFICATION
Marigolds are annual flowering plants in the sunflower/daisy family Asteraceae. The two most popular species are the Tagetes patula (French marigold) and the Tagetes erecta (African marigold). They are native to South America, Mexico and the southwestern United States.
GROWING MARIGOLDS FROM SEEDS
Marigolds are easy to grow from seed and the French variety will bloom all summer until the first frost. They can either be started indoors from seed (4-6 weeks before the last frost) or directed seeded outdoors after danger of frost has passed. In addition, marigolds do not require light to germinate. They will germinate in three to five days in temperatures above 65°F. Some varieties of marigolds will bloom in only five to six weeks, however the average time to bloom is eight weeks.
If starting seeds indoors, any size container can be used if there is good drainage. First, plant seeds in a soilless planting medium and cover the container with plastic wrap. Next, place the container in a warm area or on a seedling heat mat. Once the seedling emerges, remove the plastic wrap. Place the container in a window or under artificial lights for at least 6 hours a day. After the first true leaves develop and before the seedling is transplanted, it is important to ‘harden off’ the transplants before being planted in the ground.
HARDENING OFF
Hardening off is the process of gradually acclimating the plant to the outdoors. This process can be done in a cold frame or by simply placing the plants outdoors for a couple of hours each day for one to two weeks. For a full guide on starting plants from seeds, see my blog post titled “The complete guide to starting plants from seeds indoors”.
Marigolds can also be purchased as transplants from most garden centers.
Single Flower French Marigold (Jaguar)
Double Flower African Marigold
CARING FOR MARIGOLDS IN THE GARDEN
Light: Marigolds like full sun with at least 6 hours of sunlight a day and are not bothered by heat.
Soil: Marigolds are not fussy about their soil, but it is always good to have soil that is well-drained and amended with organic matter (e.g. the addition of compost and/or manures). Compost can be made at home or purchased from a garden center. For information on making compost at home, reference my blog titled “Recipes for Compost”. It is best to work compost into the soil in the fall for a spring planting.
Spacing: Follow the guidelines on the back of the seed package for plant spacing. French marigolds should generally be spaced 8-10 inches apart while the larger African varieties should be spaced 10-12 inches apart. Marigolds planted in containers can become crowded if planted too close together.
Water: Marigolds are drought tolerant and so be careful not to overwater. Allow the soil to dry out between watering. In containers, marigolds will require more frequent watering. When first planting marigolds, give a good watering.
Fertilizing: Marigolds can be fertilized with phosphorus but nitrogen should be applied sparingly. Too much nitrogen will encourage the plant to put more energy into the leaves and less into flowering. Look for a fertilizer with NPK (Nitrogen-Phosphorus-Potassium) proportion of 5-10-5 and apply monthly during the growing season.
Companions: Marigolds can be interplanted within a vegetable garden to attract pollinators. Contrary to popular belief, research has concluded that marigolds are not effective at reducing insect damage on vegetable crops.
CUTTING AND PRUNING
The best time to cut marigolds is first thing in the morning. Place in warm water after cutting. Strip the stem of its leaves and place in a vase with fresh warm water. After cutting, marigolds will keep for at least one week in a vase; remember to change the water often. In addition, marigolds can be dried by cutting and hanging upside down until dry.
To ensure that your marigolds continue to produce new flowers, remove the old flowers in a process called ‘deadheading’. This will allow the plant to redirect energy to producing new flowers.
PROPAGATION
It is easy to save seeds from marigolds. Only save seeds from open-pollinated varieties as saving seeds from hybrid plants is unreliable. Follow the process outlined below to save marigold seeds:
- Allow the flower head to dry on the stalk until it becomes brown
- When the flower is dry and brown, cut the flower from the stalk
- Let the dried flower heads sit for a couple of days on a paper towel to completely dry out
- Once dried, open the flower heads with your fingers and allow the seeds to fall onto a piece of paper. The seed is arrow-shaped with the top being darker than the bottom.
- Store the seeds in a paper envelope. Paper is better than a plastic bag to reduce the possibility of moisture damaging the seeds.
Dried Marigold Seed Heads
Marigold Seeds
POPULAR VARIETIES
French: Golden Gate, 2-2½ inch flowers, 18-24 inches tall
African: Jubilee, 4-inch flowers, 24 inches tall
Signet: Starfire, 2-inch flowers, 12 inches tall
POTENTIAL MARIGOLD PROBLEMS
Marigolds have few pest and disease problems which makes them a delight to grow in the garden. Occasionally, you may experience the following problems:
Common pests include:
- Spider mites can be managed with insecticidal soap.
- Aphids can be removed with a heavy stream of water on leaves or stems.
Common disease include:
- Aster Yellows is a virus transmitted by leafhoppers and is generally worse in summers that are cool and wet. Yellowing of the leaves is a symptom. If you suspect this disease, pull and dispose of the infected plant(s)
REFERENCES
Iowa State University Extension and Outreach – Marigolds
Clemson Cooperative Extension – Marigolds
University of Missouri – The Marvelous Marigold
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