The Flame Nettle is a common name for highly-colored cultivars of Coleus (Plectranthus scutellarioides or Solenostemon scutellarioides). Native to tropical regions of Southeast Asia, this plant is prized for its dramatic, vibrant foliage rather than its flowers. Its leaves display a spectacular array of colors, including reds, pinks, purples, yellows, and oranges, often in intricate patterns. While typically grown as an annual in cooler climates, the Flame Nettle can be cultivated successfully indoors year-round as a perennial houseplant.
Starting Your Flame Nettle
Propagating a Flame Nettle is commonly done using stem cuttings, which is the easiest and fastest method. To take a cutting, select a healthy stem section four to six inches long and cut just below a leaf node. Remove the leaves from the lower half of the cutting, ensuring the submerged portion is free of foliage.
Cuttings can be rooted in either water or soil, with new roots typically forming within a few weeks. For water rooting, place the cutting in a glass of water in bright, indirect light, changing the water every few days. If rooting in soil, use a moist, well-draining potting mix and cover the container with a plastic bag to maintain high humidity until new growth appears.
Growing Flame Nettles from seed is possible, though it may result in variations in color and pattern compared to the parent plant. Sow the seeds indoors eight to twelve weeks before the last expected frost, pressing them lightly onto the soil surface. Since the seeds require light to germinate, they should not be covered with soil. An ideal germination temperature is between 70 to 75°F (21 to 24°C).
Providing Optimal Growing Conditions
Vibrant coloration and successful growth depend heavily on providing the correct light exposure. The plant thrives best in bright, indirect light or partial shade, such as a location receiving morning sun and afternoon shade. Too much direct sun can cause the colorful pigments to fade or the foliage to scorch. Conversely, insufficient light results in duller colors and may lead to a spindly or “leggy” growth habit.
Flame Nettles require a consistently moist environment, but the soil must never be waterlogged, which can lead to root rot. Water the plant thoroughly whenever the top inch of soil feels dry to the touch. Signs of dehydration include sudden wilting, but the plant usually recovers quickly once watered.
A high-quality, well-draining potting mix rich in organic matter is ideal. For container growing, incorporating materials like perlite or sand can significantly improve drainage. As a tender perennial, the Flame Nettle is sensitive to cold and must be protected from temperatures below 50°F (10°C). The plant performs best in warm conditions, with an ideal temperature range of 60°F to 75°F (15°C to 24°C).
Routine Maintenance and Shaping
To maintain a dense, bushy appearance, regular pinching and pruning are necessary due to the plant’s natural upright growth. Pinching involves removing the growing tip at the end of a stem, which stops apical dominance. This action forces the plant to develop side branches, creating a fuller, more compact shape.
Flame Nettles are light feeders, but they benefit from monthly fertilization during the active growing season (spring through early autumn). Use a balanced, all-purpose liquid fertilizer, or one slightly higher in nitrogen, as the focus is on lush foliage growth. Container-grown plants generally require more frequent feeding than those planted in the ground.
Remove any developing flower spikes as soon as they appear, as flowering diverts the plant’s energy away from producing vibrant foliage. Allowing the plant to flower can also signal the end of its life cycle, causing it to become stretched and less attractive. Common pests like spider mites and aphids are generally manageable with horticultural soap or by rinsing the leaves.