Angel Trumpet plants (Brugmansia) are woody, tropical perennials highly susceptible to cold temperatures. To ensure survival in non-tropical zones, preparation is required before winter to induce a dormant state and manage the plant’s size. This process involves cutting the plant back significantly for indoor storage. Remember that all portions of Brugmansia are poisonous; gardeners must wear gloves and take necessary safety precautions.
Timing the Winter Preparation
The precise timing for preparing an Angel Trumpet for winter depends on local weather, but action must begin before the first hard frost. The signal to move the plant indoors is when nighttime temperatures consistently drop below 50°F (10°C). Moving the plant inside before freezing temperatures prevents damage to the foliage and stems.
Reducing fertilizer and water application in late summer naturally prepares the plant for dormancy. Before moving the plant indoors, thoroughly inspect the foliage for insect pests. Spider mites and aphids are common issues that thrive indoors and can rapidly infest the plant or spread to other houseplants. Treating the foliage with an insecticidal soap or horticultural oil while the plant is still outdoors prevents a pest outbreak during winter.
Specific Pruning Techniques
Pruning the Angel Trumpet reduces its overall size, making it easier to move and store until spring. Use bypass pruners that have been cleaned and sanitized to prevent the spread of disease. The goal is to reduce the plant’s height by 30% to 50%, or to a height that fits comfortably within the designated storage space.
When making cuts, prune just above a leaf node—the small, swollen area on the stem where a leaf or bud is attached. This technique encourages new, healthy growth when the plant wakes from dormancy. The most important structural element to preserve is the “Y” junction, where the main trunk splits into woody, mature branches. This mature wood produces the following season’s flowers, so cutting below the “Y” will significantly delay flowering.
Cuttings removed from the plant can be discarded or used for propagation. Once the plant is reduced, allow the pruning wounds to dry slightly before moving the plant indoors. This practice reduces the risk of pathogens entering the plant tissue during storage.
Post-Pruning Dormancy and Storage
After the Angel Trumpet is pruned and moved indoors, it requires a specific environment to complete its dormant phase. The ideal temperature for dormancy is cool but consistently above freezing, ranging from 35°F to 50°F (2°C to 10°C). A cool, unheated basement, garage, or cellar that remains within this range is an excellent storage location.
During dormancy, the plant’s metabolic processes slow down significantly, and light becomes far less important. The plant can be stored in low light or complete darkness, as it will naturally shed most, if not all, of its leaves in response to cooler temperatures and reduced light. Leaf drop is a normal sign of successful dormancy.
Care during storage involves minimal watering, providing just enough moisture to keep the root ball from desiccating. Watering approximately once a month is sufficient, ensuring the soil remains barely moist but never wet or soggy, which could lead to root rot. Monitoring the plant is limited to ensuring the root ball does not turn bone dry and confirming the trunk remains firm, indicating the plant is alive and awaiting the return of spring.