Unfortunately, mandevillas are tropical plants and can’t withstand temperatures much below 50 degrees. If you want to keep your mandevilla alive over the winter, bring it inside as a houseplant during the cold season.Click to see full answer. Beside this, how do you overwinter a Mandevilla indoors? Winterizing Mandevillas If you’re short on bright light or space, you can bring the mandevilla indoors and store it in a dormant state. Put the plant in the sink and drench the soil thoroughly to wash out pests that may be lurking in the potting mix, then cut it back to about 10 inches.Beside above, can Mandevilla live inside? The plants are not winter hardy in most zones of the United States and have a temperature minimum of 45-50 F. (7-10 C.). Unless you are in the tropical south, you will need to grow mandevilla as a houseplant. This plant has particular needs and growing mandevilla vine indoors can take some space. Keeping this in consideration, what is the lowest temperature a Mandevilla can tolerate? Since 45 to 50 °F is the minimum temperature that can be tolerated by mandevilla, plants should be moved indoors for the winter. Before bringing them indoors, examine them carefully for pests.How do you prune a Mandevilla for the winter?Cut back half the vines to ground level in winter since the resulting growth will cause a blush of flowers near the base of the plant. Snip off the vines just above a set of leaves using your pruning shears. Discard the pruned vines into a green waste can.