French marigolds will bloom from early summer through fall and because their blooms are smaller, they aren't as affected by bad weather. The color range on French marigolds is much broader than the yellow, orange and gold of African marigolds. French marigolds also come in rich reds, mahogany and bi-colors. Signet Marigolds Tagetes tenuifolia Signet marigolds bloom prolifically with very small flowers on compact, mounded plants with ferny foliage. The blooms are about the size of a dime with a single row of petals around a yellow center.
Flowers can be yellow, orange, gold, mahogany or bi-colored.
While signet marigolds don't need deadheading, it will help to cut the whole plant back an inch or two when the weather gets hot and it will fill back out as the weather cools. The most notable triploid marigolds are the Zenith and Nugget series. Zeniths flowers are an interesting combination of crested and anemone types. Even though it is an attractive plant, it is grown primarily for its herbal value since it doesn't bloom all season like other marigolds. Inc. All rights reserved.