Begonia burkillii blue is a captivating plant known for its distinctive blue coloration. This sought-after begonia offers unique visual appeal, setting it apart from other foliage plants.
The Unique Blue Iridescence
The blue sheen of Begonia burkillii blue is not due to a pigment, but rather a phenomenon known as structural color. This optical effect is created by specialized nanostructures within the plant’s cells, called iridoplasts, which are densely packed with uniformly arranged thylakoid membranes, forming a photonic crystal structure. This arrangement allows the plant to selectively reflect blue light, particularly in low-light conditions.
The blue iridescence is most pronounced in dim light, mimicking its natural rainforest habitat with limited direct sunlight. This structural coloration enhances photosynthesis by improving light capture in shaded environments. It can also directly increase the quantum yield of photosynthesis by 5-10% under low-light conditions. In brighter light, the blue sheen may become less apparent as the plant adjusts its light-harvesting mechanisms.
Cultivation and Care
Light Requirements
Begonia burkillii blue thrives in indirect, filtered light, mimicking its native shaded understory environment. Direct sunlight can scorch delicate leaves and diminish the plant’s blue iridescence. Indoors, place it near a north or east-facing window, or a diffused west window to block direct afternoon sun. If growing in a terrarium, ensure it does not receive too much direct light to maintain the blue sheen.
Watering Practices
Maintaining consistent moisture without waterlogging is important for Begonia burkillii blue. The soil should be kept moist but not soggy, as these plants are susceptible to root rot. Allow the top inch or two of soil to dry slightly between waterings before rehydrating. Watering at the base of the plant is recommended to prevent fungal leaf diseases such as powdery mildew. Proper drainage is important; always use a pot with drainage holes.
Humidity Needs
High humidity is important for Begonia burkillii blue, reflecting its tropical origins. An ambient humidity level between 60% and 90% is recommended. Methods to increase humidity include placing the plant on a pebble tray filled with water, using a room humidifier, or growing it in a terrarium environment. Consistent humidity helps prevent leaf browning and keeps the foliage healthy.
Potting Mix and Soil
A well-draining, airy, and slightly acidic potting mix is suitable for Begonia burkillii blue. A rich, moisture-retentive blend that provides good aeration, mimicking its natural forest floor habitat, is ideal. Components such as peat moss, perlite, and orchid bark can be used to create an appropriate substrate. Some growers also recommend incorporating worm castings for added nutrients.
Temperature Considerations
Begonia burkillii blue prefers stable temperatures, ranging from 61°F to 80°F (16°C to 27°C). While it can tolerate some fluctuations, avoid extreme temperature changes or cold drafts, which can stress the plant and cause leaf drop. Cooler nighttime temperatures, around 55°F to 64°F (12°C to 18°C), can also be beneficial, mirroring its Himalayan foothills origin.
Fertilization
Fertilization should be done sparingly for Begonia burkillii blue. During the active growing season (spring and summer), a balanced liquid fertilizer diluted to half strength can be applied every two to four weeks. If the plant is primarily grown for its foliage, a balanced fertilizer is appropriate. Reduce or stop fertilization during the plant’s dormancy period, in fall and winter.
Propagation Methods
Propagating Begonia burkillii blue can be achieved through stem or leaf cuttings. For stem cuttings, select a healthy stem with a few nodes (points where leaves grow). Make a clean cut just below a node using sterilized scissors and remove any lower leaves. The cut end can be dipped in rooting hormone before planting in a moist potting mix, ensuring the node is buried.
Leaf cuttings offer another method, utilizing the plant’s regenerative capabilities. A healthy leaf can be removed cleanly at its base, then cut into smaller sections, ensuring each contains a major vein. Alternatively, the entire leaf can be used. Gently press the leaf cuttings into a moist growing medium, ensuring the veins are in contact with the substrate. Both methods benefit from a warm, bright location with indirect sunlight and consistent moisture for rooting.
Common Issues and Troubleshooting
Growers of Begonia burkillii blue may encounter several common issues, often related to environmental factors. Leaf browning or crispiness indicates insufficient humidity or underwatering. Increasing humidity through methods like pebble trays or humidifiers, and ensuring consistently moist soil, can help. Wilting can signal either overwatering, leading to root rot, or severe underwatering. Checking soil moisture and ensuring proper drainage are important to addressing wilting.
A lack of the distinct blue iridescence might occur if the plant receives too much light or is not in optimal conditions. Moving the plant to a shadier spot with indirect light can help restore the vibrant blue sheen. Common pests include spider mites, aphids, and mealybugs. Regularly inspecting the plant and treating infestations with insecticidal soap or neem oil can help manage these pests.
Fungal diseases like powdery mildew and root rot can affect begonias, often due to high humidity and poor air circulation or overwatering. Ensuring good airflow and avoiding overly wet soil can prevent these issues.