Impatiens (Impatiens walleriana) are popular shade-loving plants often treated as annuals because they cannot survive freezing temperatures. These tropical perennials can be successfully overwintered indoors, even though they complete their life cycle in a single growing season in most climates. Preparing them for winter requires careful timing and a significant reduction in size, allowing the plant to survive and return to the garden the following spring.
Deciding on the Overwintering Method
Before cutting back, the gardener must choose between two primary methods for saving impatiens: overwintering the entire plant or taking stem cuttings. Bringing the entire plant indoors is the simplest approach, provided the plant is healthy and already in a container. This method requires adequate indoor space for a potted plant. If the impatiens were planted in the ground or if space is limited, taking cuttings is more practical. Cuttings are also useful if the mother plant is large or shows signs of decline. The chosen method dictates the intensity of subsequent pruning.
Timing and Preparation Before Cutting
Timing is crucial to prevent cold damage, as impatiens are highly sensitive to low temperatures. They show stress when temperatures consistently drop below 50°F (10°C) and can be irreversibly damaged by frost. Bring plants inside when nighttime temperatures are reliably above 45°F (7°C) but before they reach 55°F (13°C).
Preparation must include a thorough inspection for outdoor pests that could infest other houseplants. Common pests like aphids or spider mites must be removed by thoroughly spraying the plant with water or insecticidal soap. Remove any yellowed, dead, or diseased foliage completely to ensure the plant is clean and healthy before cutting begins.
Pruning Technique for Overwintering
Cutting back impatiens reduces the plant’s size and minimizes the shock of moving from an outdoor environment to a lower-light indoor space. For the entire plant method, cut back long, leggy stems severely to achieve a compact size. Reduce the plant’s height by about one-half to two-thirds, leaving only 4 to 6 inches of growth.
Make each cut just above a leaf node, which is the small bump on the stem where a leaf or new shoot emerges. This encourages the plant to produce new, bushy growth from the remaining nodes. If using the cutting method, clip healthy, non-flowering stem tips about 4 to 6 inches long. Remove the leaves from the lower half of these cuttings before placing the stems in water or a rooting medium.
Indoor Care and Transition Back Outside
Once pruned and moved indoors, impatiens should be treated as houseplants, adjusting care to reflect the change in environment. Impatiens do not enter true dormancy, but their growth naturally slows down due to lower winter light levels. During this period, they require less frequent watering; allow the top inch of soil to dry slightly between waterings to prevent root rot.
Place the plant in a sunny location, such as a south-facing window, to compensate for reduced winter sunlight. Withhold fertilization entirely during the winter months since the plant is not actively growing. In late winter or early spring, lightly fertilize the plant to stimulate new growth. Once the danger of the last spring frost has passed and outdoor temperatures are consistently above 50°F (10°C), impatiens can be moved back outside. This transition should be gradual, known as “hardening off,” where the plant is exposed to outdoor conditions for increasingly longer periods over several weeks.