The plant commonly called “geranium” refers to one of two types, each with a different survival strategy. The answer to whether it returns depends entirely on the species and your local winter climate. In regions with freezing temperatures, one type reliably returns on its own, while the other requires human intervention to survive and continue growing.
The Difference Between Hardy and Tender Geraniums
The plants widely known as geraniums belong to two distinct genera within the Geraniaceae family, and their hardiness differs significantly. This distinction determines whether the plant is a true perennial that withstands winter or a tender variety that cannot tolerate frost.
True Geraniums (Hardy Perennials)
True geraniums, often called cranesbills, are the hardy perennial members of the family. These plants are native to temperate regions of the Northern Hemisphere and have evolved mechanisms to survive cold winters. As temperatures drop and daylight decreases, the above-ground foliage of these plants dies back naturally. Their energy is stored securely in their root systems and crown below the soil surface, ready for spring regrowth. Cranesbills are typically hardy in USDA zones 3 through 9, meaning they are built to withstand annual freezing and thawing cycles.
Common Geraniums (Tender Perennials)
The brightly colored, popular bedding plants sold in pots and hanging baskets are botanically classified as Pelargonium species, not true geraniums. These plants are native to South Africa, a region with a warm, Mediterranean-like climate. Their cellular structure lacks the cold tolerance needed to survive frost; any temperature below freezing causes fatal damage. In their native environment or in tropical zones 10 and above, they are true perennials, growing year-round. However, in most North American and European climates (zones 9 and below), they are functionally treated as annuals, as they cannot survive the winter outdoors without special overwintering methods.
Overwintering Tender Varieties
Since Pelargoniums are not hardy in most climates, gardeners must take proactive steps to save them from a killing frost. This involves moving them into a protected, frost-free environment to interrupt their natural cycle. There are three primary methods for achieving this survival.
Overwintering as Houseplants
The simplest method is treating the plants like temporary houseplants by bringing the entire potted specimen indoors before the first hard frost. Before moving them inside, the plant should be pruned back by about a third to a half to reduce its size and remove any damaged foliage. The potted plant should be placed in a sunny window or under a grow light, ideally where the temperature remains cool, around 60 to 65°F. Watering must be significantly reduced during the winter months, only providing moisture when the topsoil feels completely dry to the touch.
Storing as Bare Roots
A second, more space-efficient technique is storing the plant in a state of semi-dormancy as a bare root. The entire plant is dug up from the garden, and the soil is gently shaken off the roots. The prepared plants are then hung upside down or placed loosely in paper bags or cardboard boxes in a cool, dark, and dry location, such as a cool basement or unheated garage. The ideal storage temperature range is between 40°F and 60°F, which is just above freezing but cool enough to prevent active growth. The roots may need light misting or brief soaking every few weeks to prevent complete desiccation until spring.
Taking Stem Cuttings
The most effective method for generating new stock is taking stem cuttings from the parent plant in late summer or early fall. Taking cuttings avoids the need to store the large mother plant and yields several new plants for the next season. Healthy, 3-to-4-inch stem tips are cut just below a leaf node, and the lower leaves are stripped away. These small sections are then rooted in a moist, sterile medium like perlite or potting mix, typically taking about six to eight weeks to develop a viable root system.
Encouraging Robust Seasonal Regrowth
Whether you are managing a hardy cranesbill or an overwintered Pelargonium, proper pruning and maintenance are necessary for vigorous regrowth and abundant flowering. The timing and severity of the cut depend on the plant type.
Regrowth for Cranesbills
For hardy cranesbills, the goal is to encourage a second burst of blooms after the first flowering period, which usually occurs in early to mid-summer. This technique involves cutting the entire plant back hard, sometimes nearly to the ground, after the initial flowers fade. This radical cut, sometimes referred to as “the chop,” stimulates the plant to produce a fresh flush of foliage and new flowers that last well into the autumn. Following this severe pruning, a feeding with a high-potassium liquid fertilizer will help support the energy required for the second round of growth.
Regrowth for Pelargoniums
Overwintered Pelargoniums also require attention to transition successfully back into the garden. In late winter or early spring, before moving the plants outside, any leggy, spindly, or dead stems must be removed. Plants stored as dormant bare roots should be potted up and cut back to approximately four inches (10 cm) to stimulate strong, bushy growth from the base. For plants overwintered as actively growing houseplants, pinching back the growing tips of the stems will encourage side-branching, which leads to a denser, more attractive form once they are returned to their outdoor location.