Ice plants are vibrant, succulent ground covers known for their fleshy foliage and daisy-like flowers that shimmer in the sunlight. The question of whether an ice plant will return each year is a common one because the name is used for several different types of plants. The confusion arises because some varieties are true, cold-hardy perennials, while others are tender plants that will not survive a harsh winter. Determining your specific plant’s species and your local climate are the only ways to definitively answer this question.
The Critical Difference: Hardiness by Species
The plants most commonly sold as “ice plants” belong to two distinct groups with very different survival characteristics. The truly perennial ice plants are primarily species of Delosperma, which are often called hardy ice plants. These varieties originated in the mountainous regions of South Africa, such as the Drakensberg, where they evolved to withstand freezing temperatures and even snow cover. For example, Delosperma cooperi and certain cultivars are reliably perennial, often surviving winter temperatures down to USDA Hardiness Zone 5.
In contrast, other plants labeled as ice plants, such as those from the Mesembryanthemum and Dorotheanthus genera, are tender perennials or annuals. These types are typically grown for their brilliant color and cannot tolerate freezing weather. Outside of frost-free regions, the foliage and roots of these tender varieties will be killed by the first hard frost, meaning they must be replanted annually. This difference in origin explains the divide, as the hardy Delosperma evolved in high-altitude cold, while the tender species come from milder coastal or desert regions.
Understanding Climate and Winter Survival
For any plant to return reliably, its inherent cold tolerance must align with the local climate conditions, which is measured using the USDA Hardiness Zone system. This system divides North America into zones based on the average annual minimum winter temperature. A hardy ice plant rated for Zone 5, for instance, is genetically capable of surviving the lowest expected temperature in that zone.
However, cold is not the only factor, as winter moisture is often more damaging to these succulents than temperature alone. Ice plants store water in their fleshy leaves, and if the soil remains wet during a deep freeze, the plant’s cells can burst, leading to root and crown rot. Even a perennial Delosperma in its correct hardiness zone may fail if it is subjected to extended periods of cold, wet soil. Gardeners must confirm their specific variety’s listed zone range to ensure a match with their geographic location.
Essential Winter Preparation
Gardeners who have confirmed they are growing a perennial Delosperma in a suitable zone must focus their winter care on managing moisture. The primary goal is to ensure the plant remains dry through the cold season, preventing root rot and freeze-induced cell damage. Preparation begins in the fall by gradually reducing or completely stopping irrigation. This reduction encourages the succulent foliage to dehydrate slightly, making it more resistant to winter temperatures.
Excellent drainage is paramount for the long-term survival of perennial ice plants. They thrive in loose, sandy, or gravelly soil, and heavy clay should be amended extensively to improve water flow. Applying a layer of dry mulch, such as gravel or coarse sand, around the base of the plant helps protect the crown from excess surface moisture. This protective layer ensures that snowmelt and winter rain do not cause the plant’s roots to sit in saturated soil.
In regions with prolonged snow cover or very wet winters, some gardeners use a light covering, such as a row crop cover, to shield the plants. This prevents the foliage and crown from staying perpetually damp, which is a common cause of winter loss. Avoid applying rich organic mulches like compost, as they retain too much moisture and encourage winter growth, making the plant susceptible to damage when the first hard freeze arrives.