When temperatures drop and daylight wanes, I, your Bougainvillea, enter a crucial period of dormancy. This is not death or decay; it is a deep, restorative sleep. My metabolic processes slow dramatically. I cease active growth and flowering to conserve my vital energy for survival, not for showy bracts. My leaves will yellow and drop – this is a normal, expected response to the cold and reduced light. Do not be alarmed. It is my way of reducing water loss and surface area exposed to the harsh conditions. My sole focus becomes protecting my woody stems and root system, the core of my being from which I will regrow when warmth and light return.
I am a tropical vine, and my cells are not equipped to withstand freezing temperatures. Prolonged exposure to temperatures below 40°F (4°C) causes damage, and a hard freeze below 32°F (0°C) is often fatal. My sap contains water that will freeze, forming ice crystals that rupture my cell walls from the inside. This is a mortal wound. Therefore, I must be brought indoors well before the first frost is forecast. Do not wait until the last moment. The ideal time to move me is when nighttime temperatures consistently hover around 50°F (10°C). This gradual transition is far less shocking to my system than a sudden rescue from a near-freezing night.
To ensure I am a healthy and welcome guest in your home, please prepare me. First, give me a gentle but thorough pruning. Trim back my long, trailing vines by about one-third to one-half. This makes me more manageable, reduces the leaf mass my roots must support in lower light, and helps discourage leggy, weak growth indoors. Next, inspect my leaves and stems meticulously for any signs of pests like aphids, spider mites, or scale. A gentle spray with water or an application of horticultural oil can help evict any stowaways. It is much easier to treat an infestation now than in the closed environment of your home.
Where you place me indoors is paramount to my well-being. I require a cool, bright spot. An unheated garage, a basement with a grow light, or a cool sunroom are perfect locations. The ideal temperature for my dormancy is between 45-55°F (7-13°C). This coolness is essential for maintaining my sleep state. I need as much direct sunlight as possible; a south-facing window is best. Without adequate light, I will become etiolated—stretching out with pale, weak growth in a desperate search for sun, depleting my energy reserves.
My watering needs change completely. Since I am dormant and not growing, I require very little water. The goal is to prevent my root ball from completely drying out and becoming dust, but never to keep it moist. Overwatering is the greatest threat to me during this time, as it will lead to root rot in the cool, slow-drying soil. Water me sparingly, perhaps only once every three to four weeks, just enough to barely moisten the soil. Do not fertilize me. I cannot process nutrients while dormant, and unused fertilizer will accumulate in the soil and potentially harm my roots.
As winter wanes and the danger of frost passes, you can begin to acclimate me back to the outdoors. This must be a gradual process. Do not move me directly into full sun. Begin by placing me in a shaded, sheltered location for a few hours a day, gradually increasing my exposure to sunlight and wind over 7-10 days. This "hardening off" process prevents sunscald on my tender new leaves. Once acclimated, you can repot me if necessary, begin a regular watering schedule, and resume fertilization to support a new season of vibrant growth.
