Begonias, known for their vibrant blooms and diverse foliage, are popular garden additions. As tender perennials, they cannot endure freezing temperatures, making winterization essential in colder climates. Protecting them ensures their survival and allows them to flourish again.
Identifying Your Begonia Type for Winterization
Accurately identifying your begonia’s type is the initial step for successful winterization, as methods vary significantly. The two primary categories relevant for winter care are tuberous and fibrous begonias.
Tuberous begonias grow from a thick, fleshy tuber, a swollen underground stem, often producing large, showy flowers. Fibrous begonias, also known as wax begonias or Semperflorens begonias, possess a traditional, thin root system. Their leaves are typically waxy and round, and they produce smaller, more numerous flowers. Other types, such as Rex and rhizomatous begonias, generally share winter care requirements with fibrous begonias, often involving bringing them indoors.
Winterizing Tuberous Begonias
Winterizing tuberous begonias involves preparing their tubers for a dormant period. Begin when foliage yellows, typically before the first hard frost, reducing watering to encourage natural decline.
Carefully dig up the tubers, allowing ample space around them to prevent damage. After removal, gently shake off any loose soil but avoid forceful cleaning.
Allow tubers to cure or air-dry for several days to weeks in a cool, dry, well-ventilated area to prevent rot during storage. Once cured, remove any remaining dried soil, stems, or roots.
Store cured tubers in a cool, dark, dry, frost-free location, ideally between 5 to 10 degrees Celsius (40 to 50 degrees Fahrenheit). Place tubers in a cardboard box or paper bag, layering them with a dry medium such as peat moss, vermiculite, sawdust, or perlite to keep them dry and prevent contact. Periodically check the stored tubers throughout winter for any signs of shriveling or rot.
Winterizing Fibrous and Other Begonias
Fibrous begonias, along with types like Rex and rhizomatous begonias, are typically brought indoors for winter. Transition them indoors before the first frost, ideally when nighttime temperatures consistently drop below 10 degrees Celsius (50 degrees Fahrenheit), to prevent cold damage.
Before moving plants indoors, inspect them thoroughly for any pests or diseases. Cleaning up dead or yellowing foliage and pruning back overly leggy growth can also be beneficial.
Once inside, provide these begonias with bright, indirect light, such as from a south-facing windowsill during winter. Watering frequency should be reduced during the indoor period, allowing the top inch or two of soil to dry completely between waterings.
Maintaining average room temperatures, generally between 18 to 23 degrees Celsius (65 to 73 degrees Fahrenheit), is suitable. Indoor air can be dry, so increasing humidity around the plants, perhaps with a pebble tray or humidifier, can support their health. Some begonias may continue to grow slowly, while others might go into a semi-dormant state, possibly shedding some leaves initially.
Bringing Begonias Out of Winter Storage
The process of reawakening begonias in spring prepares them for outdoor planting. Begin this transition in late winter or early spring, approximately six to eight weeks before the last expected frost, allowing plants to establish new growth before outdoor conditions become consistently warm.
For tuberous begonias, pot the tubers in a well-draining potting mix with the concave side facing upwards, covering them lightly with about 2.5 to 5 centimeters (1 to 2 inches) of soil. Provide warmth and bright, indirect light to encourage sprouting, and water sparingly until new shoots appear.
Fibrous and other indoor-overwintered begonias benefit from a gradual increase in light and water. If they have become root-bound, repotting into a slightly larger container with fresh potting mix can promote vigor.
Before moving any begonia outdoors permanently, acclimate them through hardening off. This involves gradually exposing them to increasing periods of outdoor light and temperature over a week or two, preventing shock when planted outside after all danger of frost has passed.