Begonias are popular ornamental plants prized for their vibrant flowers and striking foliage, often used to bring continuous color to shady garden spots and containers. Native to tropical and subtropical regions, they prefer warm, humid conditions and cannot tolerate cold temperatures, especially frost. The question of whether a begonia will return each year depends entirely on two intertwined factors: the specific type of begonia planted and the local climate where it is grown. For most gardeners, keeping a begonia alive year after year requires manual intervention to bypass the limitations of cold weather.
The Two Main Types of Begonias
The survival mechanism of a begonia is directly tied to its root structure, which fundamentally separates the most common varieties into two categories: tuberous and fibrous-rooted. Tuberous begonias, known for their large, showy flowers, grow from a specialized underground storage organ called a tuber. This tuber is a swollen, fleshy stem that stores energy and water, allowing the plant to enter a natural period of dormancy when conditions become unfavorable.
When temperatures drop, the above-ground growth naturally dies back, but the tuber below the soil surface remains alive and dormant, acting as a survival package. This root structure allows the plant to regenerate new growth from the stored energy once warm weather returns in the spring. In contrast, fibrous-rooted begonias, such as the common wax begonia, possess a traditional, shallow root system made up of fine roots. These varieties lack the specialized tuber or rhizome needed to sustain the plant through a cold period.
Lacking a substantial energy reserve and dormancy mechanism, the entire plant structure of a fibrous begonia is susceptible to cold damage. The foliage and shallow roots are easily killed by freezing temperatures. Consequently, these types are grown as annuals in most climates and must be replanted the following year.
Begonia Survival and Climate Zones
The ability of a begonia to return annually is heavily influenced by the local climate, specifically the winter temperature extremes. Begonias are categorized as tender perennials because they are not adapted to survive freezing temperatures. Hardiness zones, such as those established by the USDA, determine a begonia’s outdoor survival.
In the warmest zones (USDA zones 9 through 11), where frost is rare, many varieties can remain in the ground and regrow year after year without special protection. However, for the majority of gardeners in zones 8 and colder, winter temperatures drop low enough to kill the plant. Even the specialized tuber of a tuberous begonia will rot in cold, frozen, or excessively wet soil conditions.
In regions with a distinct winter, begonias planted outdoors behave as annuals, dying off completely once the first hard frost arrives. Gardeners must manually intervene to protect the plant from the cold if they wish for it to return the next spring. Only a few select varieties, like the hardy begonia (Begonia grandis), can tolerate temperatures down to zone 6.
How to Ensure Your Begonia Returns Next Year
For gardeners in climates with freezing winters, the perennial nature of begonias can be maintained by manually overriding the cold season through specific overwintering techniques. The method chosen depends on the begonia’s root type, as a dormant tuber requires different care than an actively growing fibrous-rooted plant. Successfully preserving a begonia means providing a safe, temperature-controlled environment until the threat of frost has passed.
Overwintering Tuberous Begonias
Overwintering tuberous begonias involves allowing the plant to naturally enter its dormant phase after the first light frost causes the foliage to yellow and die back. The tubers must then be carefully lifted from the soil before a deep freeze can destroy them. After lifting, the tubers should be dried or “cured” in a warm, dry location for several days to harden the outer skin and prevent rot.
Once cured and free of excess soil, the tubers must be stored in a cool, dry, and dark location, such as a basement or garage, where the temperature is consistently above 45°F. The stored tubers should be nestled in a material like dry peat moss, vermiculite, or sawdust to prevent shriveling. They need to be checked periodically throughout the winter, and any tubers showing signs of mold or softening should be discarded to prevent decay.
Overwintering Fibrous-Rooted Begonias
For fibrous-rooted begonias, or cane types like angel wings, the strategy is to treat them as temporary houseplants, as they do not have a natural dormancy period. These plants must be brought indoors before the first frost, often while still in their pots.
Once inside, these active begonias require bright, indirect light near a window to sustain growth throughout the winter. Watering should be reduced compared to summer months, but the soil should not be allowed to dry out completely.
Spring Reintroduction
In the spring, once all danger of frost has passed and night temperatures consistently remain above 50°F, the plants can be moved back outside. Overwintered tubers can be started indoors, or the indoor plants can be gradually re-introduced to the outdoor environment. This manual process ensures the plant’s survival, allowing it to return year after year.