The legendary plantswoman and gardener Margery Fish once famously advised: ‘When in doubt, plant a geranium.’
A lot of us must have taken her advice because today hardy geraniums (cranesbills) are one of the most popular herbaceous perennials. At the centennial RHS Chelsea Flower Show in 2013, visitors voted Geranium Rozanne (= ‘Gerwat’) as Plant of the Centenary.
Hardy geraniums are easy to grow and generally adaptable, with species that are at home in the cool comfort of woodlands while others thrive in the baking harshness of screes. In addition, the loose and relaxed character of geraniums fits well with the informal planting styles that have dominated gardens for the past 60 years.
The popularity of geraniums and the commercial success of Geranium Rozanne (= 'Gerwat') has spurred on nurseries and plant breeders to introduce many new cultivars and hybrids. Many new introductions are certainly exciting plants: Margery Fish would not be disappointed.
HARDY GERANIUMS IN BRIEF
What A genus of 420 species of hardy annuals and perennials valued for their adaptability, their ease of cultivation and their abundant flower production. Thousands of cultivars and hybrids have been bred.
Origins Geraniums are found in every continent apart from Antarctica, mainly in temperate regions. Common in woodlands and open meadows, they have also adapted to shallow soils and freezing temperatures at high altitudes. Season Mainly summer-flowering, from May to September.
Size From small alpines 10cm tall to herbaceous perennials 1.2m tall.
Conditions A few species prefer cool, shady conditions but most thrive in sunny, open situations in rich, well-drained soil.
How to grow hardy geraniums
Where to grow hardy geraniums
Most geraniums are robust and resilient plants that do not require special growing conditions other than fertile soil and a sunny situation.
cultivars need good drainage and thrive in raised beds.
m,
and
are woodland plants and need shade. They suffer from mildew in very dry conditions. If this happens, the best solution is to cut the foliage back to a few centimetres from the ground.
How to care for hardy geraniums
Geraniums measuring more than 30cm tall tend to flop over and become unsightly after flowering. Cutting the plant down will produce a new flush of foliage and usually a second burst of flowers. Don’t be half-hearted about cutting back. Take a pair of shears and chop the whole plant back to about 10cm from the ground.
Geraniums or pelargoniums?
Plants in the related genus of Pelargonium are also popularly referred to as ‘geraniums’, which often leads to confusion. The famous botanist Carl Linnaeus grouped geraniums with erodiums and pelargoniums into the single genus Geranium, but during the 19th century these were separated into distinct groups and given names that related to the shape of their seedpods. Resembling the beak of a heron, erodiums acquired their name from the Greek word for heron (erodiós) while geranium’s seeds evoke the beak of a crane (geranós).
Pelargós, the Greek word for stork, provided the name for the final group, whose seedpods suggest the stout bill of this other long-legged bird. Vernacular names of cranesbill, heronsbill and storksbill are still used to describe each group. The important difference is in the shape of the flower: geraniums have five equally sized and regularly arranged petals, whereas the flowers on pelargoniums have two upper and three lower petals. Read about how to grow angel pelargoniums.
Geranium sawfly
The larvae of geranium sawfly can munch holes in the leaves of hardy geraniums, in late spring and early summer and again in late summer. They can be difficult to spot, as they drop from the plants when disturbed, but they look like tiny grey caterpillars, around 12mm long. Although the plant looks unsightly, its long-term health is usually unaffected.
21 of the best hardy geraniums
Geranium Rozanne (= ‘Gerwat’)
Producing a mass of flowers throughout the summer, from June to October, Geranium Rozanne (='Gerwat') was found in Rozanne Waterer’s Somerset garden in 1989. Once established, it forms a wide, neat clump. Geranium 'Rozanne' (='Gerwat') was named the Royal Horticultural Society's Plant of The Centenary at the 100th RHS Chelsea Flower Show in 2013, voted for by members of the public. It produces small, violet blooms that have red streaks and white centres and has bright green foliage. It is an ideal ground cover plant and looks good at the front of a border in all types of gardens, including cottage gardens and traditional herbaceous borders.
50cm. RHS H7, USDA 4a-8b.
Geranium ‘Orion’
Geranium ‘Orion’ appeared in Holland in the late 1990s as a seedling from the popular Geranium ‘Brookside’. The luminous lavender-blue flowers (said to be named after the most luminous constellation in the sky) are 5cm wide, with darker violet veins, and cover the plant in June and then again in August. It is a large hardy geranium that looks good in the middle of a border and can be used as a ground cover plant. Geranium 'Orion' holds the prestigious RHS Award of Garden Merit. 80cm. RHS H7, USDA 3a-9b.
Geranium cinereum ‘Sophie’
A compact dome with large (2.5cm diameter) flowers mainly in May and June and sporadically thereafter. Will grow in sun or part shade but needs good drainage, especially in winter. 15cm. USDA 4a-9b.
Geranium wallichianum ‘Rosetta’
Deep-pink flowers with magenta veins on this selection made by Dutch nurseryman Hans Kramer. This hardy geranium flowers from mid-June through to September. 40cm (60cm spread). USDA 5a-8b.
Geranium ‘Lilac Ice’
Plantsman Michael Steggles spotted this hardy geranium growing in a batch of Geranium Rozanne. It has delicate, pale-lilac flowers from June to September and looks good at dusk, when the flowers seem to glow. 40cm.
Geranium cinereum ‘Alice’
Probably the largest flowers of a Geranium. cinereum cultivar over evergreen foliage. Flowers profusely in July and again in September. The hardy geranium was introduced by the Devon nursery Border Alpines. 15cm. USDA 4a-9b.
Geranium wallichianum Havana Blues
This is much more compact than most Geranium. wallichianum cultivars. It flowers from the end of June through to September and its hardy bright-blue flowers have distinct magenta veins on the petals. 35cm. USDA 5a-9b.
Geranium ‘Sirak’
Lucent, lilac-pink flowers in June and July and then again towards the end of August as the temperature drops. This hardy geranium will grow in part shade as well as full sun. 50cm. AGM. USDA 5a-8b.
Geranium cinereum 'Signal'
A cultivar raised in Germany in the 1990s. It forms a neat dome of evergreen foliage that has a silvery-grey sheen. The bright magenta flowers on this hardy geranium also have a silvery tinge. 15cm. USDA 4a-9b.
Geranium ‘Ivan’
‘Ivan’ is a big, muscular plant that grows tall and has startlingly bright magenta flowers. This hardy geranium's main flowering is during June and July with a few flowers later in the year if the whole plant is cut back. 1m. RHS H7.
Geranium Dragon Heart (=‘Bremdra’)
Large, 4cm-wide, magenta flowers with a black centre and veining are produced in great abundance from June to September. 50cm (80cm spread). RHS H7, USDA 5a-8b.
Geranium 'Tiny Monster'
A vigorous, sprawling hardy geranium with vivid pink flowers that have slightly ruffled petals. The main flowering is in May and June with a second wave in late summer. 45cm (60cm spread). USDA 5a-9b
Geranium ‘Tanya Rendall’
Hardy geranium ‘Tanya Rendall’ makes an attractive ground cover of olive-green leaves covered with an abundance of dark-pink flowers in June and July. 15cm (50cm spread). USDA 6a-9b.
Geranium cinereum ‘Carol’
Another new Geranium. cinereum cultivar that starts blooming in June and continues on and off through the summer. Flowers best when given some shade from the midday sun. 15cm (25cm spread). USDA 4a-9b.
Geranium nodosum ‘Clos de Coudray’
The flowers, with rosy-purple petals that are delicately edged in white, are held on wiry stems above the plant’s glossy foliage. Needs shady, woodland conditions. 25cm (35cm spread).
Geranium wallichianum ‘Sylvia’s Surprise’
An eye-catching hardy geranium cultivar with vivid pink flowers that are up to 3.5cm wide and first appear in early summer and then sporadically until the end of autumn. Needs well-drained soil. 40cm. USDA 4a-8b.
Geranium cinereum ‘Melody’
Of the recent Geranium. cinereum cultivars, this is the one with flowers closest to red. This hardy geranium foliage is evergreen and leaves have a silvery sheen. Flowers in May and is sporadic until September. 15cm. USDA 4a-9b.
Geranium ‘Terre Franche’
Similar to ‘Philippe Vapelle’, which like this is bred from Geranium. renardii. Its grey-green, velvety leaves form an attractive dome, and the purple flowers have beautiful blue veins that are outlined in red. 50cm. USDA 5a-9b.
Geranium ‘Sweet Heidy’
A new introduction that the breeders claim is the result of a quest to produce a plant to rival Geranium Rozanne (='Gerwat'). The size and habit are similar to its competitor; flowers are lavender-blue. 50cm. USDA 5a-8b.
Geranium ‘Fay Anna’
The new foliage on this hardy geranium emerges an unexpected pink-flushed gold and matures to an olive-green before becoming flaming red and bronze in the autumn. The pale lilac flowers appear from June to August. 30cm.
Geranium ‘Rainbow’
The blue background of the petals merges with purple veining and a pink hue at the base of the petals to create an unusual effect – not quite a rainbow but attractive nonetheless. 38cm. USDA 4a-8b.
Where to buy hardy geraniums
• Ashwood Nurseries
Ashwood Lower Lane, Kingswinford, West Midlands DY6 0AE.
Tel 01384 401996, ashwoodnurseries.com
• The Beth Chatto Gardens
Elmstead Market, Colchester, Essex CO7 7DB.
Tel 01206 822007, bethchatto.co.uk
• Cranesbill Nursery
1 Waverley Road, Mossley Estate, Bloxwich, Walsall WS3 2SW.
Tel 01684 770733, cranesbillnursery.com
• Fairweather’s Garden Centre
High Street, Beaulieu,
Hampshire SO42 7YB.
Tel 01590 612307, fairweathers.co.uk
• The Plantsman’s Preference
Church Road, South Lopham, Diss, Norfolk IP22 2LW.
Tel 07799 855559, plantpref.co.uk