The succulent groundcover Sedum mexicanum ‘Lemon Ball’ (Lemon Ball Stonecrop) is valued for its vibrant, low-growing, chartreuse foliage. While relatively cold-hardy, winter requires specific care focused on managing dormancy, preventing root rot, and protecting the plant from sustained cold. Understanding this transition ensures the plant survives the dormant period and returns with vigorous growth in the spring.
Essential Pre-Winter Pruning and Inspection
Preparing the Lemon Ball Sedum for dormancy begins in the late fall before the first hard frost. The primary goal of this pre-winter work is to remove material that could harbor pests or disease. Conduct a light pruning, clipping back any stems that have become leggy or damaged throughout the growing season. This pruning helps the plant maintain a tidier, more compact structure.
Clean the area surrounding the plant’s base, removing fallen leaves, dead foliage, and organic debris. Excess organic matter traps moisture, increasing the risk of fungal infections and rot during cold, damp conditions.
Next, inspect the foliage and stems for common succulent pests, such as mealybugs or scale insects. Addressing infestations now prevents pests from thriving during winter and damaging the plant while it is dormant.
Determining Location and Light Exposure
Lemon Ball Sedum is hardy in USDA Zones 7 through 10, tolerating freezing temperatures down to about 0°F. In Zones 7 and above, ground-established plants often survive winter without significant intervention, especially if the soil drainage is excellent. Container plants in mild winter areas should be moved against a south-facing wall or beneath a porch overhang for protection from sudden freezes.
Gardeners in colder climates or those with container-grown specimens must move the plant to a sheltered location. The ideal winter resting place should be cool, aiming for 40°F to 55°F to properly induce dormancy. Avoid placing the plant in a warm, heated living space, as this prevents the necessary dormant state.
A cool garage, basement, or unheated sunroom often provides the perfect environment.
Even during dormancy, Lemon Ball Sedum requires consistent light exposure to maintain its compact shape. If kept indoors, the plant needs bright, indirect light, ideally from a south-facing window or supplemented by a grow light. Insufficient light can cause the stems to stretch awkwardly toward the light source, a condition known as etiolation. Maintaining adequate light prevents this stretching, ensuring the plant retains its dense, attractive form.
Adjusting Watering and Nutrient Schedules
The most common mistake in winter succulent care is overwatering, which rapidly leads to root rot when combined with cold temperatures and reduced metabolic activity. As the Lemon Ball Sedum enters dormancy, its need for water decreases dramatically because the plant is no longer actively growing. The plant stores sufficient moisture in its fleshy leaves to sustain it for extended periods during the winter.
During the dormant period, watering should be reduced to a bare minimum, occurring perhaps once every four to six weeks. Only apply a small amount of water if the foliage shows visible signs of shriveling or wrinkling, which indicates the internal moisture reserves are becoming depleted.
The soil must be allowed to dry out completely between these infrequent waterings to prevent the roots from sitting in cold, wet conditions. Cessation of fertilization is also mandatory during the winter months. Applying fertilizer while the plant is dormant promotes weak, leggy growth or leads to a buildup of salts in the soil.