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The best geranium varieties to grow
There is no plant in the garden more useful, more dependable, more of a thorough all-round good egg, than the hardy geranium.
There’s a geranium for every garden situation – sun or shade, damp or dry, even those intractable patches of dry shade. The foliage is handsome; they make excellent ground cover; they are untroubled by slugs and snails; and their delicate flowers, in every shade of pink, purple, white and blue, are not only pleasing in their own right, but are the perfect foil for showier plants.
Ian and Teresa Moss have a small nursery specialising in hardy and unusual perennials. It’s the kind of nursery where you’ll always find some little treasure you’ve never seen before, lovingly grown and often with some fascinating story behind it. Yet nothing gives them more delight than the humble geranium. They grow around 60 varieties.
Teresa came to geraniums on the rebound. Her first love was geums, and she was working at building up a national collection. However, when a curious accident saw the entire nursery stock mysteriously weed-killed at dead of night, she didn’t have the heart to start again. Instead, she turned for solace to geraniums.
It was a case of heart ruling head: 10 years ago, geraniums were seriously out of fashion, considered at worst thuggish, at best dull – no more than fillers around right-on prairie perennials. “But they have recently undergone a resurgence in popularity as gardeners have rediscovered their virtues,” says Ian, “helped by the release of some good new varieties offering fresh features such as interesting foliage, longer flowering seasons and neater habits.”
Here are some of their favourites.
Meet the Rozannes
One of the best known of these introductions is Geranium 'Rozanne’, voted RHS Plant of the Centenary in 2013. This vigorous mound-forming geranium has attractive marbled foliage, and bears a profusion of large blue flowers from late May or early June right through until the first frosts. It grows well in sun or part shade in any reasonable soil, and has a handy way of scrambling about among other plants that can hide a multitude of sins. It was originally found as a chance seedling in Donald and Rozanne Waterer’s garden in Kilve, Somerset, explains Ian, and is thought to include Geranium wallichianum in its parentage.
Since 'Rozanne’, a number of new hybrids with similar parentage have followed, all with the same extended flowering season. 'Azure Rush’ is a more compact version of 'Rozanne’, with lighter blue flowers and a larger white eye.
'Lilac Ice’ is slower growing than the others, but well worth the wait for its blush-white flowers, filigreed in darker pink, with fresh, light foliage that emerges lime-green in spring. It performs best in light shade, which also shows the flowers to best advantage. G. wallichianum 'Sylvia’s Surprise’ is an outstanding “doer”, offering vivid pink flowers with a white centre. But Teresa thinks 'Pink Penny’ just has the edge – similar in habit, with a neat mound of marbled foliage topped by deep pink flowers with strong and striking veining.
Equally arresting is G. wallichianum 'Havana Blues’, its strongly veined blue flowers set off by yellow-green young foliage.
“In other perennials, new cultivars have sometimes sacrificed delicacy in favour of bigger or more plentiful flowers,” says Ian, “but that’s not the case here. At first sight, some new geraniums might seem similar, especially in colour, but start looking at the size and detail of the eye and the intricate patterns of the veining, and you’ll find infinite variety. These are flowers that repay close attention.”
Fantastic foliage
No less important, but all too often overlooked, is the beauty of the foliage, says Teresa, especially in spring and early summer as the new leaves appear.
“In recent years breeders have looked to build on this quality, with a range of good introductions with interesting and unusual foliage. Some of the earliest and most striking are selections of Geranium phaeum. These are wonderful plants for moist but well-drained soil in part shade, flowering from April to June in shades from white and pale pink through to almost black. I especially like 'Margaret Wilson’, with pale amethyst flowers forming a contrast to the cream variegated foliage.
'Springtime’ is another stunner, with lime and red marbling and fabulous maroon flowers, while 'Lavender Pinwheel’ has dark green leaves heavily mottled in black with ruffled purple and mauve flowers.
There are also several handsome selections of the meadow cranesbill, Geranium pratense, with showy purple foliage. “It’s fair to say that, in terms of flower and foliage colour, the differences between them are subtle,” confesses Teresa.
The majority are blue, though 'Midnight Clouds’ has snowy white flowers that contrast beautifully with the dark leaves. They do, however, vary greatly in terms of vigour, and Ian and Teresa recommend 'Hocus Pocus’, with strong blue flowers above finely cut bitter chocolate leaves that colour best with good light levels.
Finally, we shouldn’t overlook Geranium x oxonianum, says Teresa.
Their favourite is 'Katherine Adele’, with pink-veined white flowers and scented, deeply lobed green leaves heavily marked in burgundy.
Great ground cover
The shorter-growing geraniums, such as G. sanguineum and its tribe, make superb ground cover, with well-formed foliage and dainty flowers in pink, white and purple. Flowering at no more than 1ft (30cm) high (and often much shorter), they will earn their place in the smallest garden, or even in a tub.
Modern hybrids combine neatness of form with irrepressible vigour and an impressively long flowering season. One of the best is 'Tiny Monster’ – a terrific dwarf hybrid of G. sanguineum 'Ankum’s Pride’ and G. psilostemon, which forms a fast-spreading mound of dark-green leaves, bearing large magenta flowers for months on end. In Ian and Teresa’s own garden last year, it bloomed non-stop from late April until well into December, when Teresa finally cut it down for its own good.
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Similar, but with paler pink flowers, is the deliciously named, Canadian-bred 'Blushing Turtle’. Both like free-draining soil, and are moderately drought tolerant once established. An older variety that also performs very well is pink-flowered 'Dilys’, bred by Alan Bremner in the Orkneys. Though both she and her paler sister 'Light Dilys’ are perhaps a tad more delicate in appearance, they are no less robust and long-lasting.How to grow
Most hardy geraniums are easy-going plants that don’t need feeding or cosseting. If they start to look a bit scrappy, chopping them down to the ground and letting them start again will generally do the trick. Most benefit from a trim after the first flush of flowers, which freshens up the foliage and will also encourage further blooms. They divide easily – best done in spring as they start into growth.
Harmonious partners
Teresa thinks there’s nothing to beat the time-honoured combination of romantic English roses with geraniums around their feet. She chooses low-growing blues or glossy hummocks of G. sanguineum for preference. They look just as good, she points out, with the red emerging foliage of the roses early in the season.
Ian, however, likes to see them in a mixed herbaceous border. “They are very good at making the links between the strong architectural plants, uniting uprights and horizontals, daisies and spheres. And because these modern hybrids are in flower for so long, they can become the link plants through the seasons, maintaining the colour and harmony of the border, like a chorus holding the tune while the starrier cast change around them.
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