The question of whether geraniums are perennials is not a simple yes or no answer because the common name refers to two distinct groups of plants. A perennial lives for more than two years, while an annual completes its entire life cycle within a single growing season. The confusion stems from a centuries-old mix-up in botanical naming and the different ways gardeners treat these flowers based on local climate. Understanding this botanical difference is the first step to knowing how to care for your plants.
Understanding the Geranium Identity Crisis
The plants widely sold as “geraniums” in hanging baskets and garden centers are actually members of the genus Pelargonium. These are often called Zonal Geraniums and are technically tender perennials, only hardy enough to survive winter outdoors in very mild climates (USDA Zones 9 through 11). In regions with frost, they are treated as annuals and must be replanted each spring.
The true perennial belongs to the genus Geranium, commonly known as Cranesbills or Hardy Geraniums. These are cold-tolerant perennials that reliably return each year, typically thriving in USDA Zones 3 to 8. The flowers of the hardy Geranium are small and symmetrical, while the popular Pelargonium flowers are often asymmetrical, with two upper petals distinctly larger than the three lower ones. This botanical distinction is the source of the common gardening confusion.
Care and Maintenance for True Perennial Geraniums
Hardy Geraniums (Geranium species) are valued for being resilient and relatively low-maintenance once established in the garden. Most varieties flourish in a location that receives full sun to partial afternoon shade, though some prefer more shade in hotter climates. They perform best when planted in well-drained soil that contains organic matter. During extended dry periods, providing supplemental water helps the root system establish itself, especially in the first year. A light application of a balanced fertilizer every four to six weeks during the peak growing season can encourage robust growth.
Once the initial flush of spring or early summer blooms begins to fade, the plant benefits from the “Chelsea Chop.” This technique involves cutting the plant back drastically—often by about one-third to one-half of its height—to remove the spent foliage and flower stems. This forces the plant to put energy into new vegetative growth, resulting in a tidier mound and often promoting a second, smaller wave of flowers later in the season. As temperatures drop in late fall, the hardy perennial naturally enters dormancy, and the foliage can be cut back to the ground.
Strategies for Overwintering Tender Geraniums
Since the common bedding geraniums (Pelargonium species) will not survive freezing temperatures, gardeners in colder regions must employ specific methods to keep them alive through winter.
Bringing Plants Indoors
One of the simplest methods is to treat the plant as a temporary houseplant by bringing it indoors before the first frost. Potted plants should be placed near a bright, sunny window where temperatures remain consistently above 40°F. During the indoor period, watering must be significantly reduced, only providing moisture when the top layer of soil feels dry to the touch.
Storing Dormant Roots
Another popular technique is to force the plant into a dormant state by lifting it from the ground, shaking off the soil, and storing the bare roots. These dormant plants are hung upside down or placed in paper bags in a cool, dark, and dry location. The temperature should be maintained between 40°F and 60°F, such as in a basement or garage.
Taking Cuttings
A third strategy is to take cuttings from the mother plant in late summer or early fall, which saves space and ensures a supply of new plants. Healthy, non-flowering stem segments are rooted in fresh potting mix and kept on a well-lit windowsill. Cuttings require minimal water until they are ready to be planted outdoors again in the spring. This approach allows the original, large plant to be discarded, as the smaller cuttings are much easier to manage indoors.