Winter Care for Tropical Plants in USA

Tropical plants can’t take cold. They die when the temperature goes down below freezing. 
Example of perennial tropical plants:

Jasmine, Paan / Betel leaves, Moringa / Drum Stick, ixora, Kanakambaram, Hibiscus, Mango, Guava, Sugar Apple etc.,

Here are some of the tips to handle perennial (plants that live over multiple seasons) tropical plants.

• Grow perennial plants in containers for ease of moving around.
• Move them indoors into basement or garage or living room atleast a week before frost date.
• Keep them where there is good light. If there is no natural light, consider adding a grow light.
• Target to save the plant but not to grow them. Growing them would require high resources of perfect grow light, perfect temperature of 70F+ and perfect Relative Humidity of 50%. 
  Decide if it makes sense to invest that much of resources for the plant. If, yes, go ahead.
• Many plants like Jasmine can be cut short and store indoors in hibernation mode till next spring. This saves efforts and resources. Just move them into warm area in the home and wait for spring.
• Fruiting Plants like Mango, Guava etc., can’t be cut short for hibernation. They need to be maintained with good temperature, light and relative humidity.
• Greenhouse are good but they are expensive to setup and also to maintain the heat inside. If there are good reasons to spend that kind of resources, go for it.
• Spot heaters can be used to increase the heat upto 50 in basement and garage.
• While inside, water the plants just to keep the soil moist. Add food grade Hydrogen Peroxide diluted with water to handle fungal diseases.
• Avoid fertilizers during winter period.
• Some of the large well established plants can me tried left outdoors by using special frost blankets. Try this on semi hardy varieties like hibiscus. Frost blankets can be wrapped on these plants. Ensure to avoid cold air getting to the plant by tying the bottom of the blanket with a rope. This blanket would help increase the temperature to the plant by about 5F.
• As a trial, Jasmine, Hibiscus, Moringa etc., can be cut to the ground level, add 6” thick wood much to provide warmth to the well established roots through the winter. Very high chances that the plant survives the winter and jumps back up in spring. This would help the plant with fast growth in the spring and high production. Try this method for plants that you are ok to loose.