Overwintering is the process of protecting succulents from cold weather and the low-light conditions of winter. These plants, naturally adapted to arid environments, require specific adjustments to survive freezing temperatures and reduced sunlight. Successfully overwintering succulents involves providing a controlled indoor environment and adjusting maintenance to encourage a healthy dormancy period. This guide details how to prepare and manage your succulents indoors, ensuring they remain healthy until they can return outdoors in the spring.
Determining Your Succulent’s Winter Strategy
The first step is determining whether each plant needs to be moved indoors. Succulents are categorized into two groups based on cold tolerance: hardy and tender varieties. Hardy succulents, such as many species of Sedum and Sempervivum, naturally survive freezing temperatures by reducing leaf water content and entering deep dormancy. These types should remain outdoors, as moving them inside can disrupt their cold-hardiness cycle and cause them to stretch from insufficient light.
Tender succulents, including popular genera like Echeveria, Crassula (Jade), and Aloe, must be brought indoors when nighttime temperatures consistently fall below 50°F. Exposure to frost or prolonged temperatures below 40°F causes the water stored in their cells to freeze and burst, leading to irreparable damage. Check your local USDA hardiness zone and the cold tolerance of each variety. Moving tender plants inside before the first temperature drop safeguards them against sudden freezes.
Setting Up the Essential Indoor Environment
Once tender succulents are moved inside, establishing the correct indoor environment is the most important factor for survival. Providing adequate light is often the biggest hurdle, as natural winter daylight is insufficient to prevent etiolation—a condition where the plant stretches and becomes pale while searching for light. Supplemental lighting is necessary, ideally using full-spectrum LED grow lights that mimic natural sunlight.
These artificial lights should be positioned six to twelve inches above the plants and run for 10 to 14 hours each day. This long cycle compensates for the lower intensity of the artificial light source compared to direct summer sun. A simple timer can automate this schedule, providing energy for photosynthesis and preventing leggy growth caused by light deprivation.
Temperature and Airflow
Temperature control helps encourage the plant to enter a restful state of dormancy. The ideal temperature range for overwintering tender succulents is 45°F to 55°F. This lower temperature slows the plant’s metabolism, reducing its need for water and intense light. Avoid placing succulents near heat vents or radiators, as the dry heat can stress the plants. Also, keep them away from drafty windows where temperatures can drop too low.
Good air circulation is necessary, as stagnant air contributes to fungal issues and rot. In a crowded indoor space, lack of natural airflow allows moisture to linger around the base of the plants, creating a breeding ground for pathogens. Using a small, oscillating fan set to a low speed moves the air, helping the soil surface dry more quickly and mimicking the breezy conditions these plants naturally tolerate.
Adjusting the Dormancy Care Routine
The maintenance routine must shift once the plants are settled indoors. During dormancy, the plant’s metabolic processes slow significantly, requiring a drastic reduction in water intake. Watering should be infrequent, typically once a month or less, only when the soil is completely dry and the plant shows signs of thirst, such as wrinkled leaves. Overwatering during dormancy is the most common cause of death, as inactive roots cannot absorb moisture, leading quickly to root rot.
Fertilization must be stopped entirely during winter because the plant is not actively growing. Applying fertilizer while dormant can burn the roots, as the plant is unable to utilize the nutrients. Resume feeding only when new, active growth appears in the spring, signaling the end of dormancy.
Pest Monitoring
Consistent pest monitoring is necessary, as the dry indoor environment is an ideal habitat for specific pests. Mealybugs and spider mites are common winter invaders that thrive in the lower humidity of heated homes. Inspect the leaf axils and undersides for small, cottony masses or fine webbing. Early intervention with a cotton swab dipped in rubbing alcohol or insecticidal soap is more effective than waiting for a full-scale infestation.
Reintroducing Succulents to Spring
The transition back outdoors requires a gradual approach to prevent sun damage and shock. Once the threat of frost has passed and nighttime temperatures remain above 50°F, begin the process known as “hardening off.” This acclimatization period is crucial because the leaves, softened by months indoors, lack the protective cuticle layer needed to withstand direct sun exposure.
The process involves moving the succulents to a sheltered outdoor location that receives bright shade for the first few days. Gradually increase direct sun exposure by one or two hours each day over one to two weeks. A sudden move into full sun will cause severe leaf scorch, resulting in brown or white patches.
As the plants move outdoors, slowly resume a more regular watering schedule, increasing frequency as temperatures rise and the plants show signs of breaking dormancy. Wait until the plant is fully acclimated and shows robust new growth before returning to the active-season fertilization routine. This transition ensures the succulents are healthy and ready for a full season of growth outdoors.