The most fundamental difference lies in their botanical classification. Both plants belong to the Geraniaceae family, but they are classified into separate genera. The Common Geranium (often called a "hardy geranium" or "cranesbill") is a true member of the Geranium genus. This genus contains over 400 species of perennial plants that are hardy and survive winter in many climates.
Conversely, the Scented Geranium is not a true Geranium at all. It belongs to the Pelargonium genus. This genus is native primarily to South Africa and comprises over 200 species. The common name "geranium" is a historical misnomer that has persisted in horticulture, leading to widespread confusion. Therefore, while they are related family members, they are distinct genera, much like lemons (Citrus) are distinct from oranges (Citrus but a different species).
The two plants exhibit clear differences in their physical structure. Common Geraniums (Geranium) typically have deeply lobed or dissected palmate leaves that are often somewhat rounded. Their flowers are usually radially symmetrical (actinomorphic), meaning they have a uniform appearance with five identical petals. They are valued for their reliable, often sprawling or mounding, perennial growth in garden borders.
Scented Geraniums (Pelargonium) are primarily cultivated for their highly aromatic foliage, which releases scent when touched. The leaf shapes are incredibly diverse—deeply cut, lacy, rounded, or velvety—depending on the cultivar (e.g., rose, lemon, citronella). Their flowers are generally smaller and less showy than other pelargoniums like zonal geraniums, and they are bilaterally symmetrical (zygomorphic), with usually two upper petals differing in size and pattern from the three lower ones. They have a more shrub-like growth habit and are tender perennials, often grown as annuals or overwintered indoors in colder climates.
The intended use in gardening and horticulture highlights another major distinction. Common Geraniums are almost exclusively grown as ornamental landscape plants. They are prized for their attractive foliage, which often provides brilliant fall color, and their delicate, saucer-shaped flowers that bloom profusely. They are workhorses in perennial garden design.
The value of Scented Geraniums is predominantly olfactory and practical. They are grown for their fragrant leaves, which are used in perfumery, aromatherapy, and as a natural insect repellent. The leaves are also edible and are used to flavor sugars, jellies, cakes, teas, and cocktails. While they do flower, their blooms are secondary to the sensory experience provided by the foliage.
Their growing requirements further differentiate them. Common Geraniums (Geranium) are largely cold-hardy perennials. They thrive in temperate climates, tolerating frost and returning year after year. They prefer well-drained soil and can flourish in full sun to part shade.
Scented Geraniums (Pelargonium) are tender perennials, meaning they are sensitive to frost and cold temperatures. They originate from a warmer climate and therefore require full sun and well-draining soil. In most non-tropical regions, they are treated as annuals or must be brought indoors during the winter months to survive.
