If you want a bold pop of color in the garden with a twist of drama, the African marigold is the perfect choice. Reaching 3 feet in height with gorgeous flowers, the African marigold is a bold sun-garden flower. If you are limited in space, a dwarf variety is available that stays under one foot tall. African and French marigolds didn’t make their appearance in what would become the United States until right after the American Revolution. This marigold is also known as chrysanthemum-flowered marigold, carnation or gigantea marigold. The African marigold seed takes a long time to flower from seed, so start them indoors or buy seedlings.
Blooms: Yellow, orange or cream
Native to: Mexico and Central America
Common varieties: ‘Jubilee’ series, ‘Gold Coin’ series, ‘Safari’ series, ‘Galore’ F-1 hybrids, ‘Inca’ F-1 hybrids, ‘Sumo’ F-1 hybrids and ‘French Vanilla’
French marigolds form mounds of color in the garden. The flowers are often frilly and come in a wider color range than the African marigold and are shorter than and not as upright as the African. The flowers are single, semi-double, and double or crested flowers, 1-2 inches across and can be solid or bi-colored.
Blooms: Orange, yellow or red
Habit: Is often wider than it is tall
Native to: North America and Mexico
Common varieties include: ‘Little Hero’, ‘Hero’, ‘Bonanza’, ‘Aurora’, ‘Janie’ series, ‘Discovery’ F-1 hybrids, ‘Boy O’ Boy’ series and ‘Queen’ series
An often-overlooked marigold, the Signet marigold is far more reserved than the African and French marigold. Half-inch blooms are perched atop lacey foliage. This can be a hard one to find in garden centers. Look for seeds that you can sow directly into the garden. It is a superb performer. The flowers look more like petals. They have a wonderful lemon scent and form dense 18-inch rounded mounds.
Blooms: Yellow, orange, golden
or bi-colored flowers
Native to: North America
Hybrid types include the Gem series: ‘Tangerine Gem,’ ‘Lemon Gem,’ ‘Orange Gem’ and ‘Red Gem’ another old fashioned
one is ‘Paprika’.
Caring for marigolds
A low pH level in the soil can cause iron and/or manganese toxicity. Signs of low pH issues are brown to black speckling of the foliage.
Spent flowers turn brown and are subject to botrytis, or gray mold. Deadhead spent flowers regularly.
If new plants are tall and gangly, they can be planted a few inches below grade. The stems, when planted below grade, will produce new roots.
Save the seeds in paper bags and replant the next season.
When thrips feed on the upper surface of leaves, the leaves take on a silvery color. Distorted flowers are a sign that thrips are feeding on the plant’s pollen.
Unsightly mines or tunnels in the foliage appear when leaf miners are present.
During hot and dry conditions spider mites can devastate a stand of marigolds in a short period of time. Spider mites are difficult to spot in the beginning due to their small size coupled with the fact that they live on the underside of leaves. Mites leave tiny spots on the upper surface of the leaf. When such spots are noticed, a closer investigation and possible treatment of the plant is required. Webbing on the plant indicates a severe spider mite infestation.