Dipladenia thrive in full sun and moist, well-drained soil. They don't tolerate frost so if you live in a cold-winter climate, it's best to consider these exotic annuals or bring them indoors as houseplants until warmer temperatures return. In warm-winter areas that don't experience frost (or do so only rarely), Dipladenia is an evergreen perennial that flowers on and off throughout the year.
Dipladenia and Mandevilla will flower best in full sun—six to eight hours a day—but will tolerate part shade. One of the perks of planting them in containers is the ability to move your plants as needed. If you live in a really hot area, for instance, try moving your plant to a shady spot in mid-day to ensure the leaves don't get scorched.