Lantana is a vibrant plant admired for its continuous blooms and adaptability. Understanding its temperature tolerance is important for successful cultivation across diverse climates.
Optimal Temperature Range
For vigorous growth and prolific flowering, lantana thrives in an optimal temperature range of 60-85°F (15-29°C). Within this range, the plant produces abundant clusters of colorful blooms from late spring until the first frost. Maintaining temperatures around 75-90°F (25-32°C) is particularly beneficial for optimal growth, ensuring a healthy appearance and robust foliage.
Lantana’s Heat Tolerance
Lantana withstands high temperatures and intense sun, tolerating over 100°F (38°C). It also exhibits drought tolerance once established, surviving periods with less water. However, extreme heat combined with prolonged lack of water can cause stress, leading to sunburn or wilting. The plant generally recovers well once conditions improve and proper watering resumes.
Lantana’s Cold Tolerance
Lantana’s cold tolerance varies by hardiness zone. In warmer climates (USDA Zones 8-11), it behaves as a perennial, returning year after year. Temperatures below 36°F (2°C) can induce dormancy, causing leaves to brown or fall, but the roots often remain viable for spring regrowth.
In colder zones (USDA Zone 7 and below), lantana is often grown as an annual, as it struggles to survive winter outdoors. A light frost might cause foliage dieback, but the root system can resprout in spring. However, consistent temperatures below 28°F (-2°C) or a hard freeze will likely kill the plant, as lantana is not frost-tolerant. Even in perennial zones, extended freezing temperatures can cause significant damage.
Protecting Lantana from Temperature Extremes
Protecting lantana from temperature extremes helps ensure its longevity and vibrant display. During hot spells, proper watering is important; deep and consistent watering helps the plant manage heat, though overwatering should be avoided as it can enhance heat reflection and lead to burn. Applying a layer of mulch around the plant’s base helps retain soil moisture, reducing the frequency of watering needed and keeping roots cooler. Strategic planting in locations that receive partial afternoon shade can also mitigate the intensity of direct sun exposure.
When cold temperatures threaten, especially in zones where lantana is a tender perennial, several measures can be taken. For plants in the ground, applying a thick layer of mulch over the root zone can provide insulation against freezing temperatures. Potted lantana plants should be moved indoors before the first frost, ideally to an unheated room or garage where temperatures remain above 55°F (12°C). During indoor overwintering, reduce watering to about half an inch per week and cease fertilization to encourage dormancy. Pruning plants back before overwintering, typically to 6-12 inches from the ground, can also prepare them for dormancy.
Recognizing Temperature Stress
Recognizing the visual cues of temperature stress allows gardeners to intervene promptly. When lantana experiences heat stress, symptoms can include wilting, even if the soil has adequate moisture, as the plant struggles to transpire efficiently. Leaves may yellow, and flowering can be reduced or cease entirely, a condition known as bloom dormancy. Additionally, leaves might show signs of sunburn, such as lighter color, dry or withered tips, curling, or rolling at the edges.
Conversely, cold stress manifests with distinct signs that indicate damage from low temperatures. Leaves may blacken or become mushy, and stems can experience dieback, turning brittle. A general limp or droopy appearance of the foliage can also signal the plant is suffering from cold exposure. These visible changes are the plant’s way of communicating distress, indicating that its physiological processes are being negatively impacted by temperature extremes.