Marigolds are incredibly easy-going and reliable under a wide range of growing conditions. Once planted, marigolds grow rapidly with no fuss. Most thrive in full sun, taking hot, sunny exposures in stride. They can even handle the reflected heat and light of paved surfaces, as long as they get regular moisture.
Marigolds are not at all fussy about soil, accepting poor to average soil without complaint as long as it is not constantly soggy. In fact, they tend to bloom better in poorer soil. A too-rich soil stimulates lush foliage growth at the expense of flowers.