The Kohleria plant, a member of the Gesneriaceae family native to Central and South America, is a popular houseplant. These tropical herbs or subshrubs are known for their vibrant, often trumpet-shaped flowers, which display intricate spots or markings. Their velvety stems and foliage, often covered in fine hairs, make them a unique addition to indoor plant collections. Their easy care and prolific blooming habit contribute to their appeal as indoor specimens.
Kohleria Plant Care
Light
Kohleria plants thrive in bright, indirect light. An east or west-facing window is ideal, providing sufficient light without direct midday sun. Direct sunlight can scorch leaves, leading to damage. Inadequate light results in leggy, stretched growth and reduced flowering. Supplemental grow lights can be beneficial, especially during darker months, to ensure consistent blooming and compact growth.
Watering
Proper watering prevents common issues. Allow the top 2 inches (5 cm) of soil to dry out between waterings during the growing season. Overwatering can lead to root rot. Kohleria rhizomes store water, allowing them to tolerate brief dryness. Water thoroughly until it drains from the pot’s bottom, and avoid splashing water onto fuzzy leaves, as this can cause spots.
Humidity and Temperature
Kohleria plants prefer high humidity, ideally above 50%. Increase humidity using a pebble tray, a cool-mist humidifier, or by grouping plants. Avoid misting leaves directly, as fine hairs can trap moisture, leading to spots or fungal issues. Maintain average room temperatures between 65-75°F (18-24°C). Protect Kohlerias from temperatures below 60°F (16°C) and cold drafts.
Soil and Potting
Kohleria plants need a well-draining, airy, and slightly acidic soil mix. An African violet potting mix is recommended, or combine peat moss with perlite for drainage. Coarse sand, leaf mold, or humus can also be added. Pots with drainage holes are essential to prevent waterlogging and root rot. Kohlerias bloom best when slightly pot-bound. Repotting is only necessary when the plant has significantly outgrown its container, usually every 2-3 years in spring.
Fertilizing
During the active growing season (spring through summer), fertilize Kohleria plants regularly. Apply a high-phosphorus, water-soluble fertilizer (e.g., 10-30-10 or 7-9-5), diluted by half, every two weeks. A balanced 10-10-10 fertilizer applied monthly also works well. Reduce or discontinue feeding during dormancy (winter) to prevent fertilizer burn. Underfeeding is preferable to overfeeding, as Kohleria rhizomes are sensitive to excessive fertilizer.
Propagating Kohleria
Kohleria plants are easily propagated. Two effective methods are stem cuttings and rhizome division. For stem cuttings, select healthy, non-flowering stems, about 4-6 inches long with at least two sets of leaves. After cutting just below a leaf node and removing lower leaves, root cuttings directly in moist, well-draining potting mix or water. Covering the pot with a plastic bag or dome helps maintain high humidity, encouraging roots within 4-6 weeks.
Rhizome division is another straightforward propagation method for Kohlerias, as they produce rhizomes. Perform this process in spring, or sometimes autumn, during dormancy. Gently remove the plant from its pot and carefully separate the rhizome cluster into sections, ensuring each has at least one growth point. Plant individual rhizome sections just below the surface in a well-draining potting mix.
Troubleshooting Common Kohleria Issues
Promptly addressing common issues maintains Kohleria plant health. If a Kohleria fails to bloom, insufficient light is a frequent cause, as bright, indirect light is necessary for flowering. Lack of proper fertilization or incorrect temperatures can also inhibit blooming. Adequate light and consistent feeding encourage more prolific flowers.
Yellowing leaves indicate overwatering, which can lead to root rot. Allowing the soil to dry out more between waterings and ensuring proper drainage resolves this. Nutrient deficiencies can also cause yellowing, remedied by applying a balanced water-soluble fertilizer. Brown or crispy leaf edges point to low humidity or underwatering. Increasing humidity and maintaining consistent soil moisture alleviate these symptoms.
Leggy growth (stretched stems with sparse foliage) indicates insufficient light. Moving the plant to a brighter location or providing supplemental lighting encourages compact, bushy growth. Pruning leggy stems also promotes branching. While resilient, Kohlerias can attract common houseplant pests like spider mites, mealybugs, thrips, or aphids. Regular inspection and prompt treatment with organic methods, such as wiping leaves with a soft cloth and soapy water solution, manage infestations.