Ever since the Japanese Beetles arrived a decade ago I pretty much stopped growing marigolds entirely which is kind of silly because they really only attack the large-flowering varieties.
This year I sprouted a few small marigolds to use for filler plants in the front of my flowerbeds. I really like the random flower patterns of ‘Safari Bolero’:
These double marigolds grow 8 to 14 inches tall and bloom all summer into fall. Marigolds are just about the easiest annual you can grow. I’ve don’t think I’ve ever seen a diseased marigold, and most insects won’t bother them either.
The only insect exception is earwigs. If it’s a good earwig year—earwigs like a moist environment— they can strip a row of marigolds to pulp in a day or two. Fortunately you can control earwigs with slug bait. If things really get serious you can sprinkle a little Sevin dust on the foliage until the attack wanes.
Marigold prefer full sun, but they will tolerate partial-shade. Deadhead the flowers to encourage the plants to keep sending up fresh flower buds.