The question of whether begonias “come back” is common among gardeners, and the answer is not a simple yes or no. Begonias are popular ornamental plants known for their vibrant flowers and diverse foliage. Whether a begonia survives the winter depends entirely on the specific variety planted and the local climate, particularly the severity of cold temperatures. Most varieties are native to tropical and subtropical regions, making them sensitive to frost and freezing conditions.
The Three Main Categories of Begonias
Begonias are typically categorized into three main groups based on their root structure, which dictates their life cycle and hardiness. Understanding this classification is the first step in predicting a plant’s winter survival strategy. The fibrous-rooted type, commonly known as wax begonias, possess a dense network of fine, shallow roots. They are prized for their continuous blooming throughout the growing season.
Tuberous begonias are characterized by a fleshy, underground storage organ—the tuber—which allows the plant to enter a period of winter dormancy. This tuber acts as a reservoir of nutrients, enabling the plant to regrow when favorable conditions return. The third group is rhizomatous begonias, which grow from thick, creeping stems called rhizomes that typically spread along or just below the soil surface. This group is often cultivated more for its dramatic, colorful foliage than for its flowers.
Survivability Based on Type and Hardiness Zone
A begonia’s ability to “come back” is directly tied to the USDA Hardiness Zone. Outside of tropical zones (generally Zones 9 to 11), begonias are frost-tender and cannot survive a cold winter outdoors. Fibrous-rooted begonias, such as the common wax begonia, are perennials in warm climates but are treated as tender annuals elsewhere. They lack a mechanism for deep dormancy and perish with the first hard frost.
Rhizomatous begonias, including popular Rex varieties, are highly sensitive to cold and are often grown as indoor houseplants or seasonal patio plants. While a few specific cultivars, like the hardy begonia (Begonia grandis), can survive outdoors down to Zone 6 or 7, most must be protected from freezing temperatures. Their dense root structures will not tolerate cold, wet soil conditions.
Tuberous begonias represent the group most commonly intended to return, as they are true perennials that naturally go dormant. The fleshy tuber allows the plant to survive cold, but the tuber itself is not freeze-tolerant. In zones colder than 9, the tuber must be lifted and stored indoors to prevent freezing or rotting in the winter soil. This intervention allows these begonias to be saved and replanted the following spring.
Overwintering Techniques for Dormant Varieties
Tuberous begonias require intervention to successfully “come back” in most regions. The process begins in late summer by gradually reducing watering to encourage dormancy. Once the foliage naturally yellows and dies back, or after the first light frost, the tubers should be carefully lifted from the soil.
After lifting, cut the stems back, leaving a short stub of about two to three inches attached to the tuber. The next step is curing, where the tubers dry out for one to two weeks in a warm, airy space away from direct sunlight. Curing allows the outer layer of the tuber to form a protective seal, preventing rot during storage. Brush off any remaining soil, but avoid washing the tubers with water.
For winter storage, the cured tubers must be kept in a cool, dark, and dry environment where the temperature remains consistently between 40 and 50 degrees Fahrenheit. The tubers should be packed snugly in a breathable, insulating material like peat moss, vermiculite, or sawdust. This packing material helps maintain a stable moisture level, preventing the tubers from shriveling and keeping them dry to avoid fungal diseases. The dormant organ is preserved, ready to be started indoors six to eight weeks before the last expected spring frost.