Succulents store water in their thick, fleshy tissues, allowing them to thrive in arid environments. While they tolerate heat and drought, they are generally ill-equipped to handle freezing temperatures. Bringing container-grown succulents indoors for the colder months is necessary to protect them from frost damage. Although some varieties are more cold-tolerant than others, the seasonal change signals a universal need for protection from sustained low temperatures.
Critical Temperature Thresholds
The timing for moving succulents inside is dictated by the nighttime temperature forecast. Most common ornamental succulents, such as Echeveria, Crassula, and many Sedum varieties, are frost-tender. These plants begin to suffer cellular damage when temperatures consistently drop below 50°F (10°C) for extended periods.
The internal moisture stored in the leaves and stems can freeze, leading to cell wall rupture and irreparable damage. Consistent overnight temperatures in the low 50s signal that the plant’s metabolic processes are slowing dangerously. Therefore, the transition should begin when overnight lows are consistently predicted to remain near or below the 50°F boundary.
Delaying the move until the first actual frost often results in significant plant loss because damage from intracellular ice crystal formation is irreversible. Gardeners should monitor long-range forecasts and move sensitive plants indoors several days before the first projected overnight freeze. While a few varieties, like Sempervivum or hardy groundcover Sedum, can withstand freezing, the majority of popular container succulents require protection when the environment cools consistently.
Preparing Succulents for the Indoor Transition
Before moving succulents inside, a preparatory drying period is necessary to mitigate the risk of root rot. Watering should cease entirely one to two weeks before the move, allowing the soil to become completely dry. Dry soil is less hospitable to fungal pathogens and signals the plant to enter winter dormancy.
A thorough inspection for hitchhiking pests is the most preventative step against an indoor infestation. Pests like mealybugs, spider mites, and scale insects often reside in leaf axils or under pot rims, where they are difficult to spot. These pests thrive in the stable, warm indoor environment and can quickly establish a widespread population.
If pests are detected, treat the plant outdoors before the move to prevent an indoor outbreak. A light application of insecticidal soap or a localized swab of 70% isopropyl rubbing alcohol can eradicate many common soft-bodied pests. The pot should also be cleaned, removing moss, debris, or weeds from the soil surface and the container exterior.
This cleaning process minimizes the introduction of weed seeds or dormant insect eggs. Moving a plant with damp soil or existing pests dramatically increases the chances of fungal gnats, mold growth, or a widespread infestation during winter. Ensuring the plant is clean and dry sets the stage for a healthy, dormant period.
Maintaining Succulent Health Indoors
Once moved inside, the primary challenge is providing sufficient light, which is significantly reduced compared to outdoor exposure. Succulents require intense, direct light, and a south-facing window offers the best natural option. Plants placed in less optimal locations, such as north or east-facing windows, require supplemental lighting to prevent etiolation.
Etiolation is the stretching and weakening of the plant as it searches for light, resulting in pale, elongated growth. High-output LED or fluorescent grow lights are effective substitutes. They should be positioned 6 to 12 inches above the plant for 12 to 14 hours per day. Consistent, strong light exposure prevents the plant from expending stored energy unnecessarily.
The indoor environment necessitates a drastic reduction in the watering schedule to mimic winter dormancy. Most succulents can go four to six weeks, or longer, without water during the cooler, darker indoor months. Overwatering is the leading cause of death for indoor succulents, as the soil takes much longer to dry without outdoor heat and airflow.
When watering is necessary, it should be a thorough drench, but only after the soil has been completely dry for at least a week. The ideal indoor temperature range for wintering succulents is between 60°F and 75°F (15°C to 24°C). Avoid placing plants near cold drafts or direct heat sources like radiators, as sudden temperature fluctuations stress the plant.