Is Marigold deer resistant?

Pungent foliage that deer generally avoid, and the plant most often recommended as a living repellent to interplant through a vegetable bed.

Treat that claim carefully. Marigolds do have real documented effects against certain soil nematodes, which is a different mechanism entirely and requires growing a dense stand and turning it in, not dotting a few plants between tomatoes. The idea that the smell deters deer or rabbits from neighboring plants does not hold up.

As a plant in its own right it is hard to fault. It flowers from planting until frost, tolerates heat and poor soil, and self-sows gently. Deadhead it and it keeps going.

Do deer eat marigolds?

Seldom. Rutgers rates marigold Seldom Severely Damaged, and NC State's entries agree in their own words: the French marigold, Tagetes patula, which is the one on this page, "is deer-resistant and drought-tolerant once established," and the taller African marigold, T. erecta, "is seldom damaged by deer." The pungent leaf, "fragrant when brushed or crushed," is the mechanism. Under heavy pressure the flower heads get eaten, as flower heads do on nearly everything, and a bed browsed to the ground has rabbits in it as often as deer.

Do marigolds keep deer out of a vegetable garden?

Not the deer. No trial consulted here shows a marigold protecting the tomato beside it, and the USDA's twenty-product repellent trial found that scent in the air around a plant did not reduce browsing unless the material reached the foliage. The nematode claim is the real one and it is a different job: NC State's instruction is to "chop up the plant once it is killed by frost and work it into the soil," a dense stand turned in, not a border of them.

Recovery

A marigold browsed in July regrows from the leaf axils and is flowering again inside a month; they "bloom from spring into fall if kept deadheaded," and a deer is a rough deadheader. The plant is 6 to 12 inches high and cheap enough that replacing one is faster than protecting it.