The plants most people call geraniums are technically perennials, but they behave as annuals in any climate with freezing winters. The confusion runs deeper than just lifecycle, though, because “geranium” is casually applied to two entirely different groups of plants. The bright, ball-shaped flowers sold in garden centers every spring are almost always Pelargonium species, tender perennials from southern Africa that die at the first hard frost. True botanical geraniums, often called cranesbills, are a separate genus of cold-hardy perennials that survive winter in the ground across much of the temperate world. Whether your geraniums come back next year depends on which plant you actually have and where you garden.
Why Two Different Plants Share One Name
In the 1700s, European botanists lumped Pelargonium and Geranium into a single genus because their seed pods look alike, both producing a long, beak-shaped structure that inspired the family name Geraniaceae. When the two genera were formally split, the common name “geranium” had already stuck to the showy South African species that were flooding European greenhouses. Gardeners never switched, and nurseries still label Pelargonium plants as geraniums on the tag. The genus Geranium itself contains roughly 400 species distributed across temperate regions and tropical mountains worldwide, and most of them are perennial, with only a handful being monocarpic (flowering once and dying).1ScienceDirect. Perennial ground cover plants as floral resources for urban pollinators: A case of Geranium species If someone hands you a “geranium” at a nursery, you need to know which genus it belongs to before you can answer the annual-or-perennial question.
True Geraniums Are Hardy Perennials
Botanical geraniums, the cranesbills, are reliably perennial in most temperate gardens. Geranium pratense, meadow cranesbill, is a well-studied example: it is a perennial forb native to neutral grasslands in Britain, Ireland, and much of Europe.2Journal of Ecology. Biological Flora of Britain and Ireland: Geranium pratense It dies back to the ground in winter and returns from its rootstock each spring. Many cranesbill species are cold-hardy into USDA zones 4 or 5, meaning they survive winter temperatures well below zero Fahrenheit.
Hardy geraniums have become one of the most popular groups of garden perennials in naturalistic and woodland planting schemes.1ScienceDirect. Perennial ground cover plants as floral resources for urban pollinators: A case of Geranium species Species like Geranium macrorrhizum, Geranium sanguineum, and the hybrid ‘Rozanne’ are widely planted as ground covers, border fillers, and pollinator resources. They spread by rhizomes or self-seeding, ask for minimal care, and in many gardens persist for decades without being divided or replanted. Their flowers tend to be smaller and more open than those of Pelargonium, with five symmetrical petals rather than the two-plus-three arrangement typical of Pelargonium blooms.
If you planted a cranesbill geranium and it disappeared after one season, the likeliest culprits are poor drainage, extreme heat, or a species that simply was not suited to your zone. A few species within the Geranium genus are annual or biennial, such as Geranium robertianum (herb Robert), which completes its lifecycle in one or two years. But these are the exception, not the rule.
Pelargoniums Are Perennial in Their Homeland
The red, pink, salmon, and white “geraniums” that fill window boxes and patio pots are overwhelmingly Pelargonium species and hybrids. In their native southern Africa, these plants are genuinely perennial. Some are subshrubs with woody stems. Others, like Pelargonium sidoides, are geophytes, meaning they store energy in underground tubers and regrow from them after dormancy.3Journal of Medicinal Plants for Economic Development. Cultivation and beneficial uses of Pelargonium sidoides DC. – A review In climates where temperatures rarely dip below about 30°F, Pelargonium plants can live outdoors year-round. Gardeners in coastal California, parts of the Mediterranean, and frost-free zones of Australia and South Africa treat them as permanent landscape plants, and some specimens grow for years into large, woody-stemmed shrubs.
In most of the United States, the United Kingdom, and northern Europe, however, a frost kills the top growth and often the entire plant. That is why nurseries sell them alongside petunias and marigolds in the spring bedding section: for practical purposes, you plant them after your last frost, enjoy them through summer and fall, and expect them to die when winter arrives. They function as annuals even though, biologically, they are not.
Overwintering Pelargoniums Indoors
Because Pelargoniums are perennials at heart, you can keep them alive through winter with a little effort. There are a few approaches, and which one works best depends on your space and tolerance for fussing with plants in January.
- Potted on a windowsill: Dig the plant before frost, pot it, cut it back by about a third, and place it in a bright, cool window. Water sparingly. It will look scraggly by March, but new growth appears as days lengthen, and you can move it outside after the last frost.
- Bare-root dormancy: Pull the plant, shake off the soil, and hang it upside down or store it in a paper bag in a cool, dark space like an unheated garage. Soak the roots briefly in water once a month or so. In spring, repot and water to wake it up. This old-fashioned method works surprisingly well for zonal types with thick stems.
- Cuttings: Take stem cuttings in late summer, root them in a small pot indoors over winter, and plant the young plants outside the following spring. This gives you fresh, vigorous stock and avoids hauling large plants indoors.
Research on geranium cultivars has compared the performance of seed-propagated versus cutting-propagated types under different conditions, including full sun, moderate shade, and heavy shade.4HortScience. Residual Effects of Chlormequat on Garden Performance in Sun and Shade of Seed and Cutting-propagated Cultivars of Geraniums Cutting-propagated cultivars (the type you might overwinter as cuttings) and seed-propagated cultivars (the type you buy as transplants each spring) can both perform well outdoors, but their growth habits and vigor differ. Cutting-propagated plants often produce more uniform, reliable results when carried over from year to year, which is one reason commercial growers lean on vegetative propagation for named varieties.
How the Two Groups Handle Stress Differently
Beyond cold tolerance, Pelargonium and Geranium differ in how they manage drought and heat. Many Pelargonium species have evolved in semi-arid southern African habitats and possess physiological tricks for conserving water. Research examining 41 Pelargonium species found that while none used obligate CAM photosynthesis (the water-saving metabolism found in succulents like cacti), many showed signs of flexible water-conservation strategies. When well-watered, they photosynthesized like typical plants, but under drought stress some shifted toward nighttime acid accumulation and reduced daytime water loss through their stomata.5PubMed Central. A phylogenetic view of low-level CAM in Pelargonium (Geraniaceae) This flexibility helps explain why Pelargoniums are famously drought-tolerant in summer gardens: they can dial back their water use when conditions get harsh without shutting down completely.
True Geranium species, on the other hand, are adapted to the cooler, moister conditions of temperate grasslands and woodlands. They generally handle cold and damp better than Pelargoniums but can struggle in prolonged heat and dry soil. If you garden in a hot, dry climate, Pelargoniums are the easier choice; in a cool, damp one, hardy cranesbills have the edge.
Scented-Leaf Pelargoniums and Their Chemistry
A subset of Pelargonium species is grown not for flowers but for fragrant foliage. Rose-scented geranium (Pelargonium graveolens) is the most commercially important, cultivated for the essential oil used in perfumery, aromatherapy, and flavoring. The signature rose-like scent comes from geraniol and citronellol, monoterpene compounds produced in tiny glandular hairs on the leaves. Research has shown that the biosynthesis of these fragrant compounds occurs in the cytosol of glandular trichomes, where a specific enzyme called a Nudix hydrolase converts precursor molecules into geraniol.6PubMed. Cytosolic geraniol and citronellol biosynthesis require a Nudix hydrolase in rose-scented geranium (Pelargonium graveolens) Different chemical varieties of P. graveolens are enriched in either geraniol or citronellol, giving cultivators the ability to select for specific scent profiles.
Scented-leaf Pelargoniums are just as frost-tender as their showy-flowered cousins, so the same overwintering rules apply. They are perennial in warm climates and functional annuals in cold ones. Many gardeners keep them in pots year-round, moving them inside for winter, because the plants are compact enough to manage on a bright windowsill and because losing a mature scented geranium to frost feels like losing a small herb garden in one night.
Which Type Should You Plant?
The choice between hardy geraniums and Pelargoniums depends less on which is “better” and more on what you want them to do in your garden.
- Year-round ground cover: Hardy cranesbills win here. Species like Geranium macrorrhizum form dense, weed-suppressing mats that come back every spring with almost no attention. They also provide foliage interest well into autumn, and some offer good fall color.
- Summer color in pots and window boxes: Pelargoniums are hard to beat. Their large flower clusters last for months, they tolerate the heat that builds up in containers on sunny patios, and they bloom continuously if you deadhead them.
- Pollinator gardens: Both genera attract bees and other pollinators, but hardy geraniums with open, accessible flower shapes are generally more useful to a wider range of pollinators. Research has explored several Geranium species specifically as floral resources for urban pollinators.1ScienceDirect. Perennial ground cover plants as floral resources for urban pollinators: A case of Geranium species
- Fragrance: Scented-leaf Pelargoniums offer a range of aromas, from rose to lemon to nutmeg, that no cranesbill can match.
You can, of course, plant both. Many experienced gardeners use hardy cranesbills as the permanent backbone of a border and tuck Pelargoniums into containers or gaps for seasonal punch. This approach hedges your bets: the cranesbills return reliably each spring, and the Pelargoniums give you a fresh palette to change up every year.
Common Misconceptions Worth Clearing Up
One persistent myth is that “zonal geraniums” and “true geraniums” are the same plant in different forms. They are not. Zonal geraniums, named for the dark horseshoe-shaped zone on their leaves, are Pelargonium × hortorum hybrids. Calling them geraniums is a horticultural tradition, not a botanical fact. If a care guide says “geraniums are frost-tender annuals,” it is talking about Pelargoniums. If a perennial catalog advertises “hardy geraniums,” it means the Geranium genus. The terminology is confusing by design, or rather by historical accident, and garden writers have been trying to untangle it for over a century with limited success.
Another common misunderstanding is that seed-grown Pelargoniums are fundamentally different from cutting-grown ones. Both are the same species, but seed-grown types tend to be more variable in flower color and growth habit, while cutting-grown cultivars are clones of a selected parent plant. If you buy a named variety like ‘Calliope’ or ‘Ivy Tornado,’ it was almost certainly propagated from cuttings. The six-packs of generic “red geraniums” at big-box stores are more likely to be seed-grown. For overwintering, cutting-grown types are often easier to maintain because you can take a fresh cutting and know exactly what you will get.
Pelargoniums in Warm Climates
If you live in USDA zones 10 or 11, or in a Mediterranean climate, Pelargoniums behave the way they do in their native habitat: as true perennials that grow year-round and can reach impressive sizes. In parts of coastal California, it is common to see Pelargonium plants that have been in the ground for a decade, with woody trunks and canopies several feet across. In these settings, the plants can become leggy and overgrown if not pruned hard once a year, usually in late winter. Some gardeners cut them back to a few inches above the soil line, and the plants flush out with vigorous new growth when warm weather returns.
Even in warm climates, Pelargoniums are not immortal. They are susceptible to root rot in heavy, poorly drained soils, and they can decline after several years as their woody stems become less productive. Many warm-climate gardeners treat them as semi-permanent plants, replacing them every three to five years rather than nursing ancient specimens. The plants also self-seed in mild climates, so volunteer seedlings sometimes pop up around the garden, which can look weedy or charming depending on your tolerance for surprise.
Hardy cranesbills, by contrast, are less at home in hot, dry climates. Species adapted to cool, moist European meadows can sulk, go dormant early, or fail entirely in places like Phoenix or inland Southern California. Gardeners in those areas who want a perennial “geranium” are better served by Pelargonium species that are already adapted to semi-arid conditions and can handle the heat without supplemental watering every day.