A genus of dramatic plants grown for their glossy leaves and showy, trumpet-shaped blooms of pink, white or red, mandevillas (Mandevilla spp.) twine gracefully around a fence, mailbox or other support. At maturity, mandevilla vines reach heights up to 30 feet. The plants survive year-round in the warm climates of U.S. Department of Agriculture plant hardiness zones 10 through 11. In cooler climates, transplant mandevillas into containers and move the plants indoors for the winter. Bring the plant inside before nighttime temperatures drop below 40 degrees Fahrenheit.
Inspect the plant closely for indications of insects or insects eggs, including the undersides of leaves and the joints of stems and leaves. Spray the plant with insecticidal soap spray mixed at a rate of 1 teaspoon to a pint of water if you notice signs of pests.
Remove dead or diseased growth by pinching leaves and stems with your fingers. Prune the plant to a height of 6 to 12 inches -- a smaller plant is easier to care for and pruning it down helps conserve the plant's energy resources during the winter.
Dig up the mandevilla. Use a sharp shovel to dig deeply to prevent damage to the roots. Plant the mandevilla, along with the root ball and attached soil, in a container large enough to accommodate the roots. Be sure the container has a drainage hole in the bottom. Fill in around the root ball with commercial potting mix.
Place the plant where it receives at least three hours of direct sunlight every day. The best temperatures for overwintering mandevilla are between 50 and 70 degrees F.
Water the mandevilla sparingly, keeping the soil on the dry side, throughout the winter. As a general rule, a light watering with tepid water every five to six weeks is adequate. Withhold fertilizer during the winter months.