How are marigolds used in the landscape?

African marigold is commonly used as a bedding plant or in containers to achieve vibrant, enduring colors. It is highly valued as a cut flower.

Do African marigolds really repel garden pests?

It has long been believed that marigolds are effective in repelling various garden pests, including mosquitoes and deer. However, these claims are mostly considered myths, despite numerous online sources touting the almost magical properties of marigolds.
One exception is that certain marigolds release a chemical through their roots that can help control specific harmful soil nematodes. It is worth noting that French marigolds (T. patula) are more likely to possess this benefit compared to African marigolds. Many gardeners who plant marigolds with the expectation of keeping rabbits, aphids, and other pests away end up disappointed. Nonetheless, marigolds do attract beneficial garden inhabitants such as bees, butterflies, and ladybugs.

If marigolds are native to Mexico, why are some called French marigolds or African marigolds?

Marigold seeds were initially introduced to Europe from Mexico by explorers in the 16th century. The variety preferred by Portuguese and later French plant breeders was dubbed "French Marigolds." On the other hand, T. erecta earned the name African marigold as its seeds reached Europe through trade routes that traversed Northern Africa.

What is a pot marigold?

Calendula officinalis, commonly known as pot marigold, is a distinct flower species that belongs to a different genus than true marigolds. Despite being in the same Asteraceae family, its flowers may look similar to marigolds or chrysanthemums. However, the foliage of pot marigold differs significantly from that of marigolds, lacking the ferny texture. Moreover, pot marigold blooms earlier and for a shorter period than true marigolds, typically flowering in May and June.