Swedish Ivy (Plectranthus verticillatus) is a popular plant, appreciated for its attractive cascading foliage and relative ease of care. While often grown indoors, it can also serve as a groundcover in suitable outdoor climates. Temperature significantly influences the plant’s health and vigorous growth. Understanding its ideal temperature range and limits is important for cultivating a thriving Swedish Ivy.
Ideal Growing Temperatures
Swedish Ivy thrives in average room temperatures. The optimal range is generally between 60°F to 75°F (15°C to 24°C). Maintaining temperatures within this range supports robust growth and vibrant foliage. Consistency is beneficial, as Swedish Ivy prefers stable conditions.
During the active growing season, from spring through summer, temperatures between 70-75°F (21-24°C) are particularly favorable. Even during cooler indoor months, the plant performs well when temperatures remain between 60-65°F (16-18°C). This consistent warmth helps the plant maintain its lush appearance and encourages steady development.
Cold Tolerance and Protection
Swedish Ivy is sensitive to cold, and prolonged exposure to low temperatures can cause significant damage. While it can tolerate brief periods as low as 50°F (10°C), temperatures consistently below this threshold will stress the plant. It is particularly frost-tender and will not survive freezing temperatures. In USDA growing zones 10-11, where it can be grown outdoors year-round, the temperature should not fall below 30°F (-1°C).
When temperatures drop too low, Swedish Ivy may exhibit stunted growth, leaf discoloration, or tissue damage. Leaves might turn black or brown, or become wilted and droopy. To protect Swedish Ivy from cold, especially outdoor plants in cooler climates, bring them indoors before the first frost. Indoors, avoid placing the plant near drafty windows, air conditioning vents, or heating sources that can cause sudden temperature changes. If a cold snap is expected, temporarily moving the plant to a warmer location or using a heating mat can provide additional protection.
Heat Tolerance and Protection
Swedish Ivy can tolerate temperatures up to about 80°F (27°C), but prolonged exposure to higher temperatures can lead to stress. It can briefly withstand up to 100°F (38°C), but this requires increased attention. Excessive heat accelerates water loss, potentially leading to dehydration.
In hot conditions, Swedish Ivy may show signs of wilting or scorched leaves. To mitigate heat stress, provide shade during the hottest parts of the day, particularly for outdoor plants or those in bright window exposures. Increasing humidity through misting or placing the pot on a pebble tray can help compensate for increased evaporation. Ensuring good air circulation also helps dissipate heat. During heat waves, increase watering, preferably in the morning, to keep the plant adequately hydrated.
Recognizing Temperature Stress
Observing your Swedish Ivy for specific visual cues can help identify temperature stress. If the plant is too cold, leaves may show discoloration, appearing yellow, brown, or purplish. Stunted growth is another indicator of prolonged cold exposure. In severe cases, leaves may shrivel and drop.
Conversely, signs of excessive heat often include wilting or leaf scorch, which manifests as pale yellow or white patches, brown edges, or crispy tips. Leaves may also curl inward or twist to reduce their exposed surface area. These symptoms signal that the plant’s environmental conditions need adjustment. Addressing these signs promptly by modifying the plant’s location or care routine can help restore its health.