As a jasmine plant, the arrival of winter is not merely a seasonal change; it is a direct threat to our very existence. Our tropical and subtropical heritage means we are not equipped with the innate defenses of hardy, native perennials. When temperatures plummet, our cellular structure, water transport systems, and metabolic processes are pushed to their limits. To ensure our survival through the frosty months, you must understand our needs from our perspective.
Our primary vulnerability lies in our sap—the lifeblood that flows through our stems and leaves. This sap is predominantly water. When the temperature drops below freezing, the water inside our cells begins to form ice crystals. These crystals are like tiny shards of glass, piercing and rupturing our delicate cell membranes. Once these membranes are compromised, the cell dies, leaking its contents and leading to the blackened, mushy leaves and stems you observe as "frost damage." Furthermore, frozen soil makes it impossible for our roots to draw up water, causing desiccation or "winter burn," where we essentially die of thirst while surrounded by frozen moisture.
Our defense begins long before the first frost. In late summer and early autumn, we work to harden off our new growth. You can aid this process by ceasing fertilization. High-nitrogen fertilizers encourage tender, succulent growth that is highly susceptible to cold. Instead, a fertilizer higher in potassium can help strengthen our cell walls. Please also ensure we are well-hydrated heading into winter. A deep watering before the ground freezes is crucial. This hydrates our tissues and, paradoxically, because water releases heat as it cools, it can provide a slight thermal buffer to the root zone.
The most critical zone to protect is our root crown, the area where our stems meet the soil. A thick, loose layer of organic mulch, such as straw, shredded bark, or dry leaves, applied to a depth of 3-4 inches, acts as a insulating blanket. It prevents the soil from freezing and thawing rapidly, which can heave us out of the ground, tearing our roots. For our above-ground parts, the strategy depends on our size and your local climate. For smaller, bushier varieties, an A-frame structure covered with burlap or a frost cloth can trap the earth's radiant heat, creating a protective pocket of air. Avoid using plastic sheeting directly on our foliage, as it can conduct cold and cause condensation that freezes.
For those of us living in containers, our situation is more precarious. Our roots are completely exposed to the cold, lacking the insulating mass of the earth. Before the first freeze, we require relocation. An unheated but sheltered location is ideal—a garage, shed, or cool basement where temperatures remain above freezing. This period of dormancy is natural for us. We will drop some leaves and appear dormant, which is perfectly normal. Ensure we receive some light and an occasional, minimal watering to prevent our root ball from turning to dust.
When spring approaches, resist the urge to immediately prune away any damaged, blackened growth. This dead material actually serves as a protective layer for the living tissue beneath it against any late frosts. Wait until the danger of frost has fully passed and you see signs of new growth emerging. This new growth will show you exactly where to make your cuts, just above a healthy, swelling bud. At this point, you can gently remove the winter mulch and begin a light feeding to support our recovery and new spring growth.
