Kohleria aka Kohleria

Kohleria thrives in a light, well-draining potting mix similar to what African Violets prefer. Use a peat moss-based mix with perlite added for improved drainage—a ratio of two parts peat to one part perlite works well. You can also combine leaf mold, coarse sand, peat, and humus for a more complex blend. The key is ensuring excellent drainage, as soggy soil quickly causes rhizome rot. Always use containers with drainage holes.

Kohleria prefers relative humidity above 50% but will tolerate lower household levels. Use a cool-mist humidifier or place the pot on a humidity tray filled with pebbles and water. Importantly, never mist Kohleria directly—the fuzzy, hairy leaves trap moisture which can cause leaf spots and fungal problems like botrytis. Keep plants away from heating vents and air conditioning that dry the air.

Feed Kohleria every two weeks during spring and summer with a high-phosphorus water-soluble fertilizer (such as 10-30-10) diluted to half strength. The higher phosphorus promotes flowering. Alternatively, orchid fertilizers work well for Kohleria. Stop fertilizing entirely during winter, especially if the plant enters dormancy. Resume feeding when new growth appears in spring.

Kohleria thrives at average room temperatures between 65-75°F (18-24°C) year-round. As a tropical plant native to Central and South America, it cannot tolerate cold—never expose it to temperatures below 60°F (16°C). During winter dormancy, if you choose to let the plant rest, temperatures between 50-60°F (10-16°C) are acceptable for stored rhizomes, but active plants should remain warm.

Kohleria propagates easily through several methods. Rhizome division is the simplest—separate rhizomes in spring when repotting and plant each in its own pot. For stem cuttings, take 4-inch (10 cm) tip cuttings with at least one pair of leaves, place in moist potting mix, and cover with plastic or a cloche to maintain humidity. Cuttings root in about 4-6 weeks. You can also root cuttings in water first. Seeds are available commercially but are less reliable than vegetative methods.

Kohleria typically reaches 12-24 inches (30-60 cm) in height with a spread of 12-18 inches (30-45 cm), making them well-suited for indoor growing. Some species like Kohleria allenii can reach up to 4 feet (1.2 m), while dwarf varieties stay much smaller. With an upright growth habit, they can become leggy without pruning. Under optimal conditions, expect moderate growth of 6-12 inches (15-30 cm) per year, reaching full size in 2-3 years.

Kohleria is native to tropical regions of Central and South America, with its center of diversity in Colombia. According to Kew Gardens' Plants of the World Online database, the genus ranges from southern Mexico through Central America (Belize, Costa Rica, Guatemala, Honduras, Nicaragua, Panama) and into South America (Colombia, Ecuador, Peru, Venezuela, Guyana, Suriname, French Guiana) and the Caribbean (Trinidad). Species inhabit warm lowland areas to cool high-elevation cloud forests.

Kohleria produces distinctive tubular or bell-shaped flowers in vibrant colors including red, reddish-orange, pink, yellow, and purple. The petals feature attractive spots, speckles, or markings in contrasting colors—a hallmark of the genus. Flowers typically bloom from summer through fall, though with adequate light, many varieties can flower nearly year-round. Individual plants may produce dozens of blooms at peak flowering. The bright colors and tubular shape evolved to attract hummingbird pollinators in their native habitat.

Popular Kohleria species include K. eriantha (Fluffy Kohleria) with velvety dark green leaves edged in brownish-red and large red-orange flowers; K. digitaliflora (Foxglove Kohleria) with yellowish-green bell-shaped flowers bearing crimson upper lobes; K. amabilis (Tree Gloxinia) with pink spotted flowers; and K. tubiflora with vivid red tubular blooms. Notable hybrid cultivars include 'An's Nagging Macaws' (banana yellow with plum-crimson petals), 'Ampallang' (deep pink with purple dots), 'Beethoven' (light red with dark red veining), and 'Strawberry Fields.' Many modern hybrids feature shortened dormancy periods.

Kohleria can grow outdoors only in USDA zones 10-11 (tropical and subtropical climates like southern Florida, coastal California, or Hawaii). These tropical plants cannot tolerate temperatures below 60°F (16°C) and are sensitive to excess moisture that causes rhizome rot. In most climates, Kohleria is best grown as a houseplant where temperature and humidity can be controlled. In suitable zones, plant in a shaded location with well-draining soil, protected from harsh midday sun and heavy rain.

Prune Kohleria to encourage bushier growth and more flowers. Cut stems just above leaf nodes to promote branching—without pruning, plants tend to grow tall and leggy. In spring, cut back stems that have become too tall. For young plants, pinch off the top pair of leaves when shoots have three pairs to encourage branching. You can repeat this on new side shoots. Cut blooming stems and place them in water to enjoy the flowers indoors. Regular pruning keeps plants compact and floriferous.

Repot Kohleria in spring when the plant becomes rootbound, typically every 1-2 years. The plant actually blooms best when slightly pot-bound, so only move up one pot size. Use a container with drainage holes and fresh, light potting mix (peat moss with perlite). Spring repotting also provides an opportunity to divide rhizomes for propagation. If the plant has gone dormant over winter, wait until new growth appears before repotting.

Kohleria is rhizomatous and may go dormant in winter, especially with reduced light. During dormancy, reduce watering to just enough to prevent the soil from completely drying out, stop fertilizing, and move the plant to a cooler location (50-60°F/10-16°C). Allow foliage to die back naturally. When new growth appears in spring, resume regular watering and feeding. However, many modern hybrids remain evergreen with adequate light—you can prevent dormancy by providing supplemental grow lights for 10-12 hours daily.

Kohleria is generally resilient but can be affected by common houseplant pests including mealybugs, aphids, thrips, and spider mites. Watch for cottony white masses (mealybugs), sticky residue (honeydew from sucking insects), or distorted growth. Due to their fuzzy leaves, avoid neem oil which can cause discoloration—use insecticidal soap or remove pests with alcohol-dipped cotton swabs. The primary disease concern is rhizome rot from overwatering. Ensure good air circulation and avoid wetting the foliage to prevent fungal problems like botrytis.

Yellow leaves on Kohleria typically indicate overwatering or root rot—the most common problem with this plant. Check if the soil is soggy and inspect roots for dark, mushy tissue. Reduce watering and ensure proper drainage. Yellow leaves can also result from too much direct sunlight (the fuzzy leaves are sensitive to harsh rays), nutrient deficiency during the growing season, or natural dormancy as the plant prepares for rest. If yellowing occurs with sticky residue, check for aphids or mealybugs.

Brown leaf tips or edges on Kohleria usually indicate low humidity—the plant prefers above 50% relative humidity. Brown spots on the leaves often result from water droplets remaining on the fuzzy foliage, so always water from the bottom and never mist. Brown, mushy stems near the soil line indicate rhizome rot from overwatering. Direct sunlight can also cause brown scorching on the delicate, hairy leaves. If the entire plant is browning and dying back in fall or winter, this may be normal dormancy.

Drooping in Kohleria most commonly indicates underwatering—when the soil becomes too dry, the plant wilts and may enter dormancy. Check the soil and resume regular watering; the rhizomes store water and should help the plant recover. However, drooping can also signal overwatering and root rot, so examine the roots for dark, mushy tissue. Other causes include temperature stress (too cold or hot), transplant shock after repotting, or pest infestation weakening the plant. Severely wilted plants may recover from rhizomes if the underground parts remain healthy.