Geranium Care: Annual Pelargoniums vs Hardy Cranesbills

The word "geranium" is applied to two unrelated plants — annual Pelargonium and hardy perennial cranesbill Geranium spp. Care requirements differ substantially; this guide covers both.

Pelargoniums vs. hardy geraniums: identifying what you have

The confusion between these two plants has a historical root. Swedish botanist Carl Linnaeus originally classified both under Geranium; they were later split when their differences became clear. The common name "geranium" stuck to Pelargonium in popular use, and it's never been untangled. Per Clemson Extension HGIC, the "common geranium sold in most garden centers" is botanically Pelargonium × hortorum.

Annual "geraniums" — Pelargonium × hortorum and relatives

Identifying features: Round-headed flower clusters in red, pink, salmon, coral, or white on upright stems 12–24 inches tall. Thick, round-lobed leaves often with a darker "horseshoe" band. Distinctive spicy or musky scent when leaves are bruised. These are the window-box geraniums, the bedding plants, the porch pot staples.

There are also ivy geraniums (Pelargonium peltatum), with trailing stems suited to hanging baskets, and scented-leaf geraniums (Pelargonium graveolens and others) grown for fragrant foliage. All share the same basic care requirements.

Hardiness: Perennial only in USDA zones 10–11. In zones 3–9, they are grown as annuals or overwintered indoors.

Hardy geraniums (cranesbills) — Geranium spp.

Identifying features: Smaller, more delicate five-petaled flowers in purple, blue, pink, magenta, or white, often with visible veining. Deeply lobed palmate leaves on low-mounding plants, typically 12–18 inches tall. Many have good fall foliage color. No strong scent. 'Rozanne', 'Johnson's Blue', 'Biokovo', and Geranium sanguineum are common landscape varieties.

Hardiness: Most are hardy in zones 3–8 or 4–9 depending on species. They go dormant in winter and re-emerge reliably in spring.