What’s The Difference Between Geraniums and Pelargoniums?

I’ve often heard that the showy, sun loving plants we call geraniums, are actually not geraniums but are pelargoniums. It’s confusing, so I asked horticulturist Ruth Rogers Clausen for some clarity. Here’s what she had to say.

Geraniums and pelargoniums belong to the same botanical family: the Geraniaceae. However, the common name “geranium” is often used incorrectly in reference to members of the Pelargonium genus. There are multiple species in each genus, most of which are resistant to browsing deer and often rabbits too.

True or hardy geraniums–

True or hardy geraniums (shown above) are often called cranesbills, in reference to the shape of the fruits that have elongated stigmas (the beak) and bold ovaries (the head). The symmetrical five-petalled flowers may be white or in pinks, purples or blues. Most geraniums are perennial and are valuable for flashy color in summer gardens. Popular species include: G.cinereum, gray-leaved cranesbill, has white or light pink flowers on clumps of grayish evergreen foliage. Good for rock gardens.  Other popular species:

‘Ballerina’, 6” tall, with prominently dark-veined bright pink/purple flowers.

‘Splendens’ has screaming magenta blooms on 6” plants. Late spring-summer.

G.macrorrhizum, bigroot geranium, 15” tall, is a semi-evergreen perennial with good fall foliage color. Bright crimson flowers in spring on wide spreading but not invasive rhizomes. ‘Ingwersen’s Variety’ has very light pink flowers.

G. maculatum, wild, spotted or wood geranium is perennial, native in woods across most of the Northeast. Its pink flowers on 12-24” stems attract many pollinators.

G, renardii, dwarf cranesbill, excels in rock gardens where soil is dry. Clusters of lavender-flushed, white flowers above attractive soft grayish foliage. 12”

G. sanguineum, bloody cranesbill, has cupped white-eyed magenta blooms in spring, above clumps of deeply divided foliage that turns blood red in fall. Spreads lightly by rhizomes. ‘Album’ has pure white flowers; striped cranesbill, var. striatum (syn. G. s. v. lancastriense), makes an excellent ground cover or rock garden plant.

Pelargoniums–

Pelargoniums are semi-hardy or annual plants. This group includes the bedding or zonal, scented, ivy-leaved or trailing types, along with Regal or Martha Washington geraniums. The flowers are mostly showy, with 2 upper petals and 3 lower petals, are arranged in clusters. They bloom from early summer through fall, but often are nurtured indoors through the winter as houseplants.

Bedding/zonal geraniums (P.x hortorum) are bedded out by the millions each late spring and bloom through summer. Named for the dark zones on the leaves. Take cuttings in early fall to bloom indoors.

Scented geraniums are known for their slightly fuzzy foliage in differing fragrances, especially rose, orange, nutmeg, and citronella. The foliage of these has been used medicinally for generations and is also used for flavoring in various dishes. The flowers are less showy than bedding types.

Ivy-leaved or trailing geraniums have shiny leaves shaped like those of ivy. Ideal for hanging baskets, window boxes or atop walls, colors range from white and pinks, to lavenders and deep wine red.

Regal/Martha Washington types have very attractive clusters of brightly colored, often frilly flowers. They bloom in spring and are excellent as pot plants for forcing for spring holidays. Bloom time does not continue into warm weather.