Some of the different types of marigolds are African marigolds, also known as the tagetes erecta, French marigolds, or bushy T. patula, and the rock garden marigolds, also known as dainty T. tenuifolia. There are more than 50 varieties in all.
Marigolds are known for their bright orange and happy appearance. The rock garden marigolds grow best in hot climates and have edible flowers. French marigolds are a smaller size, growing from 6 inches to 2 feet tall. African marigolds, which are sometimes called American marigolds, reach 3 to 5 feet tall.
When growing marigolds, be careful about mildew, root rot and mold.