Updated/Fact-Chacked on June 27, 2023 by Gareth James
Geraniums are perennial plants with symmetric flowers with 5 petals, whereas the pelargonium genus are not winter hardy and have irregular-sized petals on a thick stem.
Geraniums and pelargoniums are both part of the Geraniaceae family, but are two different genuses and have very different growing requirements and appearances.
As a gardening expert once told me:
Knowing the difference between geranium and pelargonium is the sign of a true gardener!
Even garden centres will label pelargoniums as ‘geraniums’, head over to your local centre and see for yourself. In this article, I will discuss the differences between the two genus and look at where the confusion came from.
Geraniums v Pelargoniums: Easy Differentiation for Beginners
Pelargoniums
The common name for pelargonium is ‘geranium’, which causes a lot of problems. Most people will not use the term ‘pelargonium’, including some of the large plant growers in the Netherlands who distribute to garden centres.
Pelargoniums are native to South Africa and like full sun, and are generally half-hardy; they will not survive a harsh winter. In the Northern Hemisphere, pelargoniums are generally used as annuals for bedding plants, traditionally used in hanging baskets.
A typical pelargonium has light and dark blotches on the foliage, as seen below.
Most pelargonium varieties have flower heads that consist of multiple flowers on a strong, tall stem. The individual flowers also have irregular-sized petals, with the upper petals being larger than the lower ones.
pelargonium flower with irregular petals – the other petals are larger than the inner ones
pelargonium flower head on a thick stem
Pelargonium varieties include: Pelargoniums are divided into these main groups Zonal pelargoniums, Ivy-leaved pelargoniums, Regal pelargoniums, Angel pelargoniums, Unique pelargoniums, and Scented-leaved pelargoniums.
I particularly like and have these three growing this season (all AGM plants) – ‘Attar of Roses’ (rose-scented leaves), ‘Lara Candy Dancer’ (scented leaves and pale mauve petals) and ‘Spanish Angel’ (lilac & magenta flowers).
10 Best Autumn Flowering Plants UK
Geraniums
Geraniums are also called ‘cranesbills’, ‘true geraniums’ and ‘hardy geraniums. This hardy genus of the Geraniaceae family are true perennial and will return each year, surviving the winter months even at -20 C. The genus has 420 species and is commonly found on most continents. In the UK, many hardy geraniums grow in the wild; here’s a variety (Geranium sanguineum) that grows in the sand dunes at my local beach.
Hardy Geraniums have flowers with five equally sized petals, unlike pelargoniums. Many varieties will also have veins like this example in my border.
My Geranium in my ‘shade pot’ attracts a lot of small beesGeranium varieties include: Geranium Rozanne (‘Gerwatt)- which won plant of the century at the RHS Chelsea flower show one year, Gaura lindheimeri, ‘Wargrave Pink’, Geranium ‘Patricia’ (purple. flowers and black centre), Geranium ‘Spessart’ (Pink)
This is one of my hardy geraniums in my shade pot, it only gets two hours of light per day.
@plantsman.io Full shade pot #plantsoftiktok #plants #gardening ♬ Sunrise
History of Pelaroniums and the Naming Confusion
Pelargoniums were originally classified as in the Geranium genus in the 1700s by botanist Carolus Linnaeus – he is single-handily responsible for all the confusion. By the 19th Century, Pelargoniums had been reclassified as a different genus within the Geraniaceae family – but this made little difference as they were being called ‘geraniums’ which became their common name.
More Geranium FAQs
Are pelargoniums and geraniums the same?
They are in the same family called Geraniaceae, but they are different plant genera.
What is the common name for Pelargonium?
Pelargoniums are commonly called ‘geraniums’, which causes a lot of confusion.
What are the two types of geraniums?
There are two types, the hardy geranium genus and pelargoniums which are treated as annuals in the UK.
Which geraniums are the hardiest?
Both Geranium ‘Rozanne’ and Geranium ‘Ivan’ have a hardiness rating of H7 – the highest rating by the RHS. These geraniums can withstand -20 C winters.
References
https://herbaria.plants.ox.ac.uk/bol/plants400/Profiles/op/Pelargonium
https://en.wikipedia.org/wiki/Pelargonium
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Gareth is the owner of Plantsman Media. Gareth lives in the North East of England and is obsessed with flowers. He has just started RHS level 2 certification.