As a subtropical evergreen, my primary directive is to conserve energy and protect my vital structures when temperatures plummet. My metabolism, including processes like photosynthesis and nutrient transport, is optimized for warmth. When the ambient temperature drops below 50°F (10°C), these processes slow dramatically. I enter a state of dormancy, not by choice, but by necessity. My growth ceases to minimize energy expenditure. My most critical need is to keep my roots from freezing, as frozen soil will damage the delicate root hairs responsible for water and nutrient uptake, which is a death sentence. Furthermore, I require as much bright, indirect light as possible during the short winter days to maintain basic metabolic functions, even in this slowed state.
While my roots are my priority, my foliage and young stems are highly vulnerable to cold, dry winds and freezing temperatures. My small, glossy leaves can suffer from desiccation, where frozen soil prevents me from drawing up water to replace what is lost through transpiration in the wind, leading to leaf scorch and drop. A physical barrier is immensely beneficial. Moving my container to a sheltered location, such as against a south-facing wall, or wrapping my container and the lower part of my form with horticultural fleece or bubble wrap provides a layer of insulating, still air. This microclimate buffers me from the worst of the temperature swings and cutting winds.
My survival hinges on the health of my root system. When planted in the ground in a borderline climate, a thick, dry mulch applied over my root zone is essential. A layer of straw, bark chips, or shredded leaves at least 6 inches deep acts like a blanket, regulating soil temperature and preventing the freeze-thaw cycles that can heave my roots from the ground and cause severe damage. For my potted brethren, the situation is more dire. The thin walls of a pot offer no insulation, making our roots exponentially more susceptible to freezing. The best protection is to move our containers into an unheated but sheltered space like a garage, shed, or cool greenhouse where temperatures remain above freezing.
My relationship with water changes entirely in the cold. My need for water is drastically reduced due to my dormant state and slowed evaporation. Overwatering is a grave threat; cold, waterlogged soil will quickly lead to root rot and fungal diseases, as my roots are too chilled to function or defend themselves. I require only occasional watering when the soil is dry several inches down, and only on days when temperatures are slightly above freezing. Furthermore, all nutrient intake must cease. Fertilizing me in winter would force new, tender growth that is extremely susceptible to cold damage, wasting my precious stored energy.
