Geranium psilostemon

12 February 2016  |  Admin

As part of a minor reshuffle of this website this is one of our old articles that is now moved here into the Blog.


Geranium psilostemon

This is the largest hardy species and well-known to many gardeners for its large magenta flowers with their black centres, putting on a good show mainly in June and July.  The display may continue if the weather is not too hot and dry, and the plant is in reasonable soil.  The name Geranium psilostemon was published by Ledebour in 1842 and means “with bare, ie hairless, stamens”, so following the tradition of naming plants by their most noticeable feature. Many gardeners make a tongue-twister of this name, but it merely uses a silent p, like psychiatrist. Some nurseries insisted on using the incorrect name Geranium armenum published by Boissier in 1867, well into the twentieth century, and some plants may well still be labeled as this, not surprising, really, considering that for more than two hundred years, the name “Geranium” is still incorrectly applied to Pelargoniums in garden centres and seed catalogues.

This species has been introduced to Britain many times from its origin in northeastern Turkey and the southwestern Caucasus, and is totally deciduous.  In  early spring the resting crowns typically show their bright red buds through the soil, rather like rhubarb, though some less common clones are greener.  The leaves are large with broad divisions, obvious if compared with G. pratense, and often have good autumn colour. The plant’s stature largely depends on the soil: in our garden on dry Breckland sand it grows to 60cm (2ft), but in a rich moist garden soil it would usually be twice that. The cultivar ‘Coton Goliath’ is the largest we know and reaches about 150cm (5ft) (unstaked!) in good soil on our nursery in an open windy site which doesn’t get irrigated. This selection has extra large tropical-looking foliage and flowers as prolifically as the usual form.

In the recent RHS trials plants of G. psilostemon with white and pale pink flowers were shown, and should be available within two or three years.  ‘Bressingham Flair’ introduced by Alan Bloom in 1969, has beautiful flowers of a much softer colour, and may suit gardeners of a nervous disposition. Unless you trust the propagator, it’s a good idea to buy this plant in flower as it has often been grown from seed, giving various colours.

In recent history, G. psilostemon has been a parent in an increasing number of hybrids. ‘Ann Folkard’ was grown from seed collected from G. procurrens by Rev.O Folkard in 1973, and is deservedly a popular garden plant treasured for its long season of interest beginning with golden spring leaves and extending well into autumn with neat magenta, black-centred flowers. In the reduced light of autumn, or in shade, the flowers take on an interesting bluish purple colour. Less strict gardeners can have a lot of fun with this plant by growing it with taller shrubs or perennials, allowing it to scramble its flowering stems among them, safe in the knowledge that all will die back to the crown in the winter and not run about like the other parent. Stricter gardeners may prefer Alan Bremner’s hybrid using the same parents: ‘Anne Thomson’ which shares the colours and long display but in rather more compact form. Alan also bred the well-known ‘Patricia’, which uses G. endressii, giving a long season of flower to a plant which is shorter and softer pink than G. psilostemon.  His ‘Nicola’, using G. x oxonianum is rather similar, but with widely spaced petals. From Holland ‘Ivan’, named after Ivan Louette, uses similar parents, but is a distinctly different plant, much shorter than typical G. psilostemon and with large rather pinker flowers, a very worthwhile addition to any garden. Other hybrids have been made with different forms of G. sanguineum. ‘Little David’ resembles a compact erect form of G. sanguineum with bright glowing magenta purple flowers. ‘Tiny Monster’ makes a much bigger plant, resembling ‘Khan’, a sanguineum hybrid with another species, though with pinker rather than purple flowers.

Just recently becoming widely available is Cyril Foster’s ‘Red Admiral’ which is a hybrid with G. sylvaticum ‘Baker’s Pink’. This flowers non-stop on the Nursery stock beds, from June till frost, giving plenty of unmistakably red flowers with a dark centre on a 60cm plant.  ‘Farncombe Cerise Star’ is a hybrid with G. x oxonianum f. thurstonianum which featured in the RHS trial. This has narrow petals similar to G. x o. f. thurstonianum in flower and leaf colour.  Even more recently, we are quite impressed by ‘Sandrine’ which is best described as being like ‘Ann Folkard’, but hairier and with bigger flowers.

G.psilostemon tends to self-seed sparingly, in our experience.  Of course all cultivars must be propagated vegetatively, and on the Nursery, species as well, as they cannot be trusted to come true from seed.  Both the species and hybrids like ‘Patricia’ which make plenty of crowns are readily divided in the traditional way. ‘Ann Folkard’ and ‘Anne Thomson’ make a very compact crown and require an experienced propagator, even then, not many plants come from a large ‘Ann Folkard’.

Geranium psilostemon and its hybrids are reliable, easy to grow perennials and provide long-lasting colour for any garden.

Jenny Fuller

© J&T Fuller 2007, permission granted for use by non-profit making clubs/societies etc to use in their newsletters and journals.  All we ask is that it is used complete with no editing and that we are credited properly (it would be nice to receive a copy of the publication as well!).