Tuberous Begonia (Group)

Basic Information

Common Name: Tuberous Begonia (Group)

Scientific Name: Begonia Tuberhybrida Group

Native Habitat: Andes region of South America.

History / Discovery / Cultivator

The Begonia Tuberhybrida Group, commonly known as Tuberous Begonias, boasts a fascinating history deeply intertwined with exploration, scientific classification, and horticultural innovation. Their story begins in the rugged, cloud-covered Andes Mountains of South America, where their wild ancestors flourished in the cool, humid understory of the rainforest. While the exact origins of the Begonia genus date back to the 17th century with its naming after Michel Bégon by Charles Plumier, the real story of the Tuberous Begonias starts in the 19th century.

The wild ancestors of the modern Tuberous Begonias were initially discovered during various botanical expeditions to the Andes. Species like Begonia boliviensis, Begonia veitchii, Begonia davisii, Begonia pearcei, and Begonia socotrana played crucial roles in the development of the Tuberhybrida Group. These species, each with unique traits such as vibrant colors, diverse flower shapes, and robust tuberous roots, were carefully collected and brought back to Europe, primarily to England and Belgium.

The key to the creation of the Tuberous Begonia Group lies in the dedicated efforts of Victorian-era horticulturists. They skillfully hybridized these Andean species, focusing on traits such as larger flower size, improved flower form (including double flowers), and a wider range of colors. Breeders in England, such as James Veitch & Sons, were pioneers in this endeavor. They recognized the potential of these exotic plants and dedicated significant resources to their development. Belgian breeders, including those in the Ghent region, also played a critical role, contributing to the improvement and diversification of the Tuberous Begonia lines.

The early hybrids were far from the showy specimens we see today. They were often smaller, less floriferous, and more delicate. However, through generations of selective breeding, the plants gradually improved. By the late 19th century, Tuberous Begonias had become incredibly popular, gracing greenhouses and gardens across Europe and North America. Their popularity extended from the grand estates to the modest home gardens, democratizing the enjoyment of these exotic blooms.

The introduction of Begonia socotrana, a species from the island of Socotra in the Indian Ocean, brought about a significant advancement. Begonia socotrana flowers in the winter, unlike the other tuberous begonias that bloom in the summer. Breeding with this species allowed for the creation of cultivars that could bloom during shorter days, expanding the blooming season. This led to the development of the Hiemalis Begonias, a group distinct from the Tuberhybrida Group but stemming from the same foundational breeding work.

The Tuberous Begonia continues to be refined and diversified. Modern breeding efforts focus on improving disease resistance, expanding the color palette further (with breeders always striving for true blues and unique color combinations), and creating more compact and weather-resistant varieties. The result is a plant with a rich history, a testament to the dedication of plant explorers and horticulturists, and a vibrant legacy that continues to bloom in gardens around the world. They have truly become a global garden staple.

Plant Care Summary

Botanical Insights

Adaptations

Tuberous begonias exhibit several remarkable adaptations. Their tuberous roots allow them to store water and nutrients, enabling them to survive periods of drought or dormancy. This is crucial in their native Andean habitats, which can experience seasonal variations in rainfall. The thick, succulent stems and leaves help to conserve water, further aiding in their drought tolerance. In cultivation, this adaptation allows them to withstand occasional lapses in watering. Furthermore, their ability to produce vibrant and diverse flower colors and forms is an adaptation to attract pollinators such as bees and hummingbirds, ensuring successful reproduction.

Propagation Methods

Tuberous begonias can be propagated through several methods. The most common and straightforward method is tuber division. Mature tubers can be cut into sections, ensuring each section has at least one “eye” or growth point. These sections are then planted in well-draining soil. Stem cuttings are also a viable option. Cuttings taken from healthy stems can be rooted in water or directly in soil. Leaf cuttings, although slower, can also be used, especially for some varieties. Another method involves starting from seed, although this can be more challenging and time-consuming. Each method offers a way to expand your collection of these beautiful plants.

Toxicology

Tuberous begonias contain soluble oxalates in all parts of the plant, but especially concentrated in the tubers. If ingested by humans, the oxalates can cause a burning sensation in the mouth and throat, excessive salivation, and difficulty swallowing. Symptoms are typically mild and resolve on their own. However, ingestion of large quantities, particularly of the tubers, can lead to more severe gastrointestinal distress. For pets like cats and dogs, the effects are similar. Symptoms include oral irritation, excessive drooling, vomiting, and difficulty swallowing. While rarely life-threatening, prompt veterinary attention is recommended if a pet ingests a significant amount of the plant. It is best practice to keep the plant out of reach of children and pets.

Common Problems

Pests:

• Aphids
• Mealybugs
• Spider mites

Diseases:

• Powdery mildew
• Botrytis blight (gray mold)
• Root rot

Other:

• Leaf yellowing: Overwatering or nutrient deficiency.
• Bud drop: Insufficient light or inconsistent watering.
• Leggy growth: Insufficient light.

Rarity & Value

Rarity:

While many common Tuberous Begonia cultivars are readily available, certain varieties, particularly those with unique flower forms, unusual colors, or heirloom status, can be considered relatively rare. Also, some specific double flower cultivars of certain colours are harder to find on the market. Rarity can also be linked to the difficulty of propagation; some varieties are more challenging to propagate, limiting their availability.

Value:

The value of a Tuberous Begonia specimen is influenced by several factors. Flower size and form play a significant role, with larger, more elaborate blooms commanding higher prices. The color and uniqueness of the flower color are also important determinants. Well-established plants with multiple blooms are generally more valuable than young or single-stemmed plants. Healthy, disease-free specimens with robust growth habits also command a premium. Finally, older, heirloom varieties can be quite valuable as collectors seek out harder to find plants.