Lantana (Lantana camara) is a vibrant, sun-loving plant prized for its continuous summer blooms in shades of red, orange, yellow, and pink. Originating in tropical and subtropical regions, it is widely cultivated as an ornamental shrub. Its popularity stems from its low maintenance needs and ability to attract pollinators like butterflies and hummingbirds. Gardeners in temperate climates often face the challenge of preserving this colorful plant through the winter months.
Understanding Lantana’s Cold Tolerance
The survival of lantana over winter depends on the local climate, typically mapped by the USDA Plant Hardiness Zone system. Lantana is reliably perennial in Zones 9 through 11, where winter temperatures rarely drop below freezing for extended periods. In these warmer zones, the plant may remain semi-evergreen or enter a brief dormancy. In colder regions, such as Zones 8 and below, lantana is usually treated as an annual plant, dying back completely and requiring replanting each spring. The plant’s top growth is not frost-tolerant and usually dies once temperatures dip below 36°F, initiating dormancy. A sustained freeze, particularly when temperatures drop to 28°F or lower, is lethal, killing the unprotected root system and preventing spring regrowth.
Strategies for Outdoor Survival
In borderline climates, such as Zone 8 or a warm Zone 7, established lantana plants can survive the winter with specific ground-level protection. The goal is to insulate the crown and the root mass just below the soil surface. Overwintering in-ground plants is a calculated risk and is only viable where deep, prolonged freezes are uncommon.
Preparation begins in late autumn, after the first hard frost has caused the top growth to die back. The dead stems should be cut back to a height of six to twelve inches above the soil line. This pruning removes the damaged material and helps the plant focus its energy on the roots.
The primary step is applying a thick, insulating layer of mulch over the plant’s crown. Organic material, such as straw, pine needles, or shredded leaves, should be piled four to six inches deep and extend well beyond the root zone. This mulch layer stabilizes the soil temperature and provides a buffer against rapid temperature fluctuations.
Proper soil management is also important for survival during cold, wet periods. Lantana requires well-draining soil to prevent water accumulation around the roots. Excessive moisture combined with low temperatures can lead to root rot, which will kill the plant. Ensuring good drainage improves the chances of the roots surviving to push new growth in the spring.
Overwintering Containerized Plants
For gardeners in Zones 7 and colder, bringing container-grown lantana indoors is the most reliable method for ensuring survival. This strategy preserves the mature plant for the next season. The transition indoors should occur before the first expected frost, typically when nighttime temperatures consistently fall below 45°F.
Before relocating the plant, it must be pruned heavily to manage its size and prepare it for reduced resources. Cutting the stems back by up to one-third makes the plant more manageable and reduces the amount of foliage maintained indoors. This is also the time for a thorough inspection to prevent the introduction of garden pests.
The plant should be checked meticulously for common indoor pests, such as whiteflies and spider mites. Any signs of infestation should be treated with insecticidal soap or oil before the plant is brought inside. This minimizes the chance of pests spreading to other houseplants.
Once indoors, there are two primary approaches for overwintering. The first is to force the plant into dormancy by placing it in a cool, dark, or low-light location, such as a basement or unheated garage, where temperatures remain between 50°F and 60°F. During this dormant state, the plant requires very little attention and should be watered only enough to prevent the root ball from completely drying out.
The second option is to keep the plant actively growing by placing it near a bright, sunny window, ideally facing south or west, where the temperature is warmer, around 60°F to 70°F. Lantana maintained in active growth will require more regular watering, allowing the top inch or two of soil to dry out between applications. This allows the plant to keep some foliage and continue slow growth throughout the winter months.