Succulents are plants defined by their ability to store water in specialized tissue, allowing them to tolerate drought conditions. The winter season presents a challenge because the combination of cold temperatures and moisture leads to cell damage and rot. Successful overwintering requires a shift in care to accommodate their natural slowing of growth, whether the plants are tropical varieties moved inside or cold-tolerant species left outdoors. This guide provides steps for managing succulents through the cold months to ensure their survival and health until spring.
Preparing Succulents for Dormancy
Pre-winter care must begin several weeks before the first hard frost to nudge succulents into a dormant state. The most important step is to gradually reduce watering frequency over four to six weeks, signaling the plant to conserve energy instead of actively growing. This water restriction is crucial because a plant that is not actively growing cannot efficiently use water, making it highly susceptible to root rot in cold or low-light conditions.
Before moving tender succulents indoors, inspect them thoroughly for pests to prevent infestations of other houseplants. Check the undersides of leaves and tight rosettes for pests like mealybugs or spider mites, removing visible pests with a cotton swab dipped in rubbing alcohol. Remove all dead leaves and debris from the soil surface and around the plant base, as this organic matter can harbor moisture and breed fungi and pests. Ensuring pots have clear, unblocked drainage holes promotes good airflow and guarantees excess water can escape immediately.
Essential Indoor Care During Winter
Indoor care is the primary strategy for frost-tender succulents that cannot handle temperatures below 40°F and must be moved inside. The goal indoors is to replicate the cool, dry conditions of their natural winter resting period, focusing on light, temperature, and minimal hydration.
Light is the most significant challenge indoors due to shorter days and lower sun angles, which can cause the plants to stretch out (etiolation). Place succulents in the brightest location possible, ideally a south-facing window, to maximize the limited winter sunlight. If natural light is insufficient for the six to eight hours of bright light many succulents need, supplemental LED grow lights should be used to maintain their compact form.
Temperature management requires placing plants away from sudden extremes, such as cold drafts near windows or direct heat from vents, which can dry them out too quickly or cause cellular damage. The ideal temperature range for wintering succulents is slightly cooler than room temperature, generally between 50°F and 55°F, which encourages deeper dormancy. Maintaining good air circulation around the plants helps the soil dry out faster and prevents the stagnant, humid conditions that encourage fungal growth.
The watering regimen is drastically reduced during indoor overwintering because metabolic processes slow down. Most succulents only need water once every four to six weeks, or less frequently, when the soil has been completely dry. Overwatering is the most common cause of death, leading to root rot because the soil takes much longer to dry in the cool, low-light environment. It is safer to err on the side of underwatering, as a succulent can survive a long time on its stored reserves.
Outdoor Protection for Cold-Tolerant Species
Certain species, such as Sempervivum (Hens and Chicks) and Sedum (Stonecrop), are cold-hardy and can tolerate freezing temperatures, sometimes down to -30°F (USDA Zone 4). For these plants, the main danger is not the cold itself, but the combination of cold and excess moisture, which can lead to rot.
Ensuring impeccable drainage is the most important factor for outdoor winter survival; plants should be in coarse, rocky soil that allows water to pass through quickly. In areas with heavy winter rain or snow, utilize microclimates, such as planting near a south-facing wall or under eaves, which offers shelter from precipitation and wind. The heat retained by a wall can provide a localized temperature buffer against extreme cold.
Physical protection can be applied when temperatures are predicted to drop below the plant’s hardiness threshold. A temporary cover of frost cloth or a bedsheet can be draped over plants when frost is forecasted to prevent ice crystals from forming on the foliage. Applying a layer of inorganic mulch, such as gravel or chicken grit, around the plant base helps insulate the roots and keeps the plant’s neck dry by preventing water from pooling.
The Spring Transition Process
When the threat of hard frost has passed and outdoor temperatures remain above 50°F, transition the succulents back to their outdoor environment. This process, known as “hardening off,” is a multi-week adjustment period that prevents sun damage and shock.
Indoor-wintered succulents are accustomed to lower light intensity; immediately placing them in direct sun will cause their leaves to scorch and turn brown. Start by placing the plants in a shaded, sheltered outdoor location for a few hours each day. Over seven to fourteen days, gradually increase the duration of sun exposure by an hour or two daily.
This slow reintroduction allows the plant cells to build up natural waxes and pigments, offering protection against the full intensity of ultraviolet light. Once the plants are fully hardened off, the watering schedule can be slowly increased to break dormancy and encourage new growth. Begin with a light watering, then gradually transition back to a deep, thorough soaking only after the soil has completely dried out, matching the increasing light and warmth.