Overwintering Hibiscus, Mandevilla, Bougainvillea and Other Tropical Plants
Try growing these tropical beauties in a bright sunny window for winter. Water thoroughly whenever the top few inches of soil is just slightly moist. Place the plants on a saucer filled with pebbles. The excess water collects in the saucer while the plants safely rest on the pebbles above the water. This increases humidity around the plant, prevents root rot caused by plants sitting in a water-filled saucer and reduces your workload.
You can also grow these plants in a cool location with minimal light and water. The goal is to keep the plants alive in a somewhat dormant state. Water thoroughly but just often enough to keep the roots from drying. It is a bit riskier, but may be the only option if indoor space is limited.
A bit more information: Don’t let unwanted pests hitch a ride indoors with your tropical plants. Isolate the plants from your other indoor plants for several weeks. Monitor for signs of insects and mites. I prefer using more eco-friendly products like insecticidal soap, Summit® Year-Round® Spray Oil (or other light weight horticulture oil) or Neem when problems occur. You will need repeat applications, but these products are safer for you, your pets and children.