Begonia thurstonii, or Thurston’s Begonia, is a classic hybrid houseplant appreciated for its distinctive ornamental leaves. Created in 1887, this heirloom plant is known for its relatively easy-care nature and ability to thrive indoors. It is admired for its velvety texture and metallic color, which distinguish it from many other varieties.
Physical Characteristics and Origin
The foliage is kidney-shaped and slightly crinkled, displaying a deep olive green to bronze hue with a glossy, metallic sheen on the upper surface. The underside of the leaf is a vivid red or burgundy.
This begonia is a shrub-like, broadleaf evergreen perennial, maintaining an upright, bushy habit year-round. It can reach a height of up to one meter, though regular pruning helps maintain a compact mound. During the summer, it produces clusters of small, bright pink flowers on red-tinted stems, complementing the rich foliage.
Optimal Growing Conditions
#### Light Requirements
The plant requires bright, indirect light to maintain vibrant leaf coloration and a compact growth habit. Place it near an east or west-facing window, shielded from direct midday sun, which can scorch the leaves. Insufficient light leads to pale foliage and a stretched-out, or “leggy,” growth pattern.
#### Soil and pH
A well-draining, slightly acidic soil mixture is recommended to prevent water retention. Use a soilless medium formulated for African violets or a custom blend of two parts peat moss to one part perlite or vermiculite. The ideal pH range is between 5.5 and 6.2.
#### Watering Practices
Ensure the soil remains evenly moist without becoming saturated, which causes root rot. Allow the top inch of the growing medium to dry out completely before watering again. Soak the soil thoroughly and allow all excess water to drain completely from the drainage holes.
#### Temperature and Humidity
This begonia thrives in warm, stable indoor temperatures, ideally between 15°C and 28°C (59°F and 82°F). It is sensitive to cold drafts and sudden temperature drops, which can cause leaf drop. Begonia thurstonii prefers high humidity levels, often requiring supplemental moisture. Achieve this by placing the pot on a pebble tray filled with water or by grouping it with other plants.
Propagation Techniques
Increasing stock is straightforward using both stem and leaf cuttings.
#### Stem Cuttings
Select a healthy, non-flowering shoot with at least two or three leaf nodes. Use a clean, sharp blade to cut just below a node, as this area contains the highest concentration of root-producing cells. The cutting can be dipped in rooting hormone before being planted in a moist, well-draining propagation mix. Covering the container with a clear plastic bag or dome creates the high-humidity environment necessary for root development, which typically occurs within a few weeks.
#### Leaf Cuttings
Select a mature, healthy leaf and cut it into wedge-shaped sections, ensuring each piece contains a portion of a major vein. Press these sections, cut-side down, into a sterile, moist growing medium. Consistent warmth and high humidity encourage new plantlets to sprout from the cut veins. Once the plantlets are large enough to handle, separate them gently from the original leaf and pot them individually.
Troubleshooting Common Issues
Improper watering is the most frequent issue, leading to symptoms like wilting or drooping leaves. Consistently soggy soil indicates root rot due to lack of oxygen and fungal growth. Conversely, crispy edges and wilting often signal underwatering or excessively low humidity.
Environmental stress can cause leaf discoloration; yellowing often signals a problem with light exposure or nutrient uptake. Sudden temperature fluctuations or cold drafts frequently cause the sudden drop of lower foliage.
Pests common to indoor begonias include mealybugs (white, cottony masses) and spider mites (fine webbing and stippling). Manage these by isolating the plant and applying horticultural oil or a cotton swab dipped in rubbing alcohol to the affected areas.