Succulents are popular plants for both indoor and outdoor cultivation due to their unique water-storing leaves and stems. Whether they can be left outside year-round depends entirely on your local environment and the specific type of succulent. Success requires careful preparation and an understanding of the plant’s biological limits regarding temperature, light, and moisture. Matching the plant’s needs to your climate allows many succulents to become permanent, low-maintenance features of your outdoor landscape.
Understanding Succulent Cold Tolerance
Temperature is the most significant factor determining if a succulent can remain outdoors through winter. Most succulents native to tropical or desert environments, often called “tender” varieties, suffer damage below 40°F (4°C) and will not survive a hard freeze. This susceptibility is due to the high water content in their fleshy leaves and stems, which ruptures cell walls when ice crystals form.
The USDA Plant Hardiness Zone map guides determining a perennial plant’s viability based on the average annual extreme minimum winter temperature. Succulents that survive freezing are “frost-hardy,” possessing mechanisms to reduce cellular water and prevent lethal ice formation. These plants often enter dormancy during the cold season, ceasing active growth until warmer weather returns. If your region experiences prolonged freezing, only truly frost-hardy species should be placed outdoors year-round.
Managing Outdoor Light and Water Needs
Outdoor placement introduces a greater risk of sunburn and overwatering compared to a controlled indoor environment. Succulents previously living indoors are not acclimated to the intensity of direct, unfiltered outdoor sunlight. Sudden exposure causes brown or black scorch marks, resulting in permanent tissue damage. The plant’s protective waxy coating, called farina, can also be rubbed off, leaving the underlying tissue vulnerable to the sun.
Outdoor succulents are highly susceptible to overwatering from unpredictable rainfall, which is the most frequent cause of their demise. Succulents store water and do not require frequent irrigation; their roots quickly rot if left in constantly damp soil. To counteract this, all outdoor succulents must be planted in extremely well-draining soil, typically a mix of potting soil and inorganic grit like perlite or pumice. Container plants must have drainage holes to ensure no standing water collects around the roots.
Identifying Hardy Versus Tender Species
The ability to withstand a full year outdoors relies entirely on the plant’s genetic origin, making species identification crucial. Tender varieties, such as Echeveria, Haworthia, and most Crassula (like the Jade plant), originate from warmer climates and must be brought indoors before the first frost. These plants are not suited for prolonged cold, even if they tolerate brief dips below freezing when the soil is dry.
Conversely, a small group of succulents is genuinely cold-hardy, allowing them to remain outside even in areas with snow and freezing. Genera like Sedum (Stonecrop) and Sempervivum (Hen and Chicks) are excellent examples of this resilience. Sempervivum, native to mountainous regions, can often survive temperatures down to USDA Zone 4, or approximately -20°F (-29°C), provided they have sharp drainage. Always confirm the specific species’ hardiness rating against your local USDA Zone before committing it to a permanent outdoor spot.
The Process of Moving Succulents Outdoors
For tender succulents that winter inside, the transition to the outdoor climate in spring must be a gradual process known as “hardening off.” This acclimatization period toughens the plant tissue and prevents shock and sun damage. Begin this process only after the danger of the last spring frost has completely passed.
Start by placing the succulents in a sheltered location with full shade for just a few hours a day. Over one to two weeks, slowly increase the duration of their time outside and gradually expose them to more direct sunlight. This measured approach allows the plant to naturally build up its defenses against the elements. In the fall, reverse this process by bringing the plants back inside well before the first significant temperature drop, typically when nighttime temperatures consistently fall below 45°F (7°C). Inspect and treat the plants for any pests before moving them indoors for winter storage.