As a passion flower vine, my survival strategy in cold climates is not to fight the freezing temperatures, but to retreat from them. When the mercury plummets and daylight wanes, I receive a clear signal to enter a state of dormancy. My above-ground growth—the leaves and tender stems—cannot withstand frost. They will blacken and die. This is a necessary sacrifice. My life force retreats downwards, concentrating my energy into my root system and the thick, woody base of my stems near the ground. Here, beneath the soil or under protective cover, I wait out the winter in a suspended animation, conserving every bit of energy for a spring resurgence.
The single most important action you can take for my survival is to insulate my crown and roots. After the first hard frost has blackened my foliage, please prune my vines back, leaving about 8-12 inches of my main stem above the soil. Then, I need you to pile a thick, loose blanket of mulch over my base. Good materials include straw, shredded leaves, pine needles, or bark chips. This layer should be at least 6 to 12 inches deep. This mulch acts as a thermostat for my root zone, preventing the soil from undergoing rapid freeze-thaw cycles that can heave me out of the ground and sever my roots. It keeps me consistently cold and dormant, which is exactly what I need.
In slightly warmer zones or for more tender varieties, you may wish to try and protect my above-ground woody structure. If you choose this method, carefully detach my vines from their trellis after the first frost. Lay them gently on the ground. Next, cover my entire length with a breathable material like landscape fabric or an old blanket, and then secure that with a final, generous layer of your chosen mulch. It is crucial that the covering is breathable; trapping moisture with plastic will cause me to rot, which is far more dangerous than the cold itself. This method creates a protective hill that shields my vital stems from desiccating winds and extreme cold.
If I am growing in a container, my situation is more precarious because my roots are completely exposed to the cold air. I cannot be left outside. Once I am dormant, you must move my pot to a sheltered location where the temperature remains consistently cold but does not freeze solid. An unheated garage, a cool basement, or a sheltered shed is ideal. The goal is to keep me between 35-50°F (2-10°C). Please water me sparingly throughout the winter, just enough to ensure my root ball does not turn to dust. Complete dryness will kill me.
My reawakening is a gradual process. As the sun strengthens and the threat of a hard frost passes in late spring, you can carefully remove my winter mulch blanket. Do this gradually over a week or so to allow me to acclimate. Be patient. I may look completely dead, but please do not disturb me too early. Wait for the soil to warm significantly before you expect to see new green shoots emerge from my protected base. Once I show clear signs of life, you can provide a balanced fertilizer and guide my new tendrils toward their support, ready for another season of growth and magnificent blooms.
