14 June 2013
Growing Hardy Geraniums
One of the most popular plants in the British garden is the hardy Geranium, mainly for it's beautiful flowers, which can last from early summer to autumn, and which range from purple via pink and white to blue. Many varieties also have attractive leaves with a range of markings and colourings, and in sizes ranging from small to dinner-plate size. A lot of the species are excellent for providing ground cover. There are over 420 species of hardy Geranium currently recognised and it can be found in every continent except Antarctica.
Plants known as Annual Geraniums are actually Pelargoniums and are very different to Geraniums although part of the same plant family.
Geraniums are tolerant of most soil types, unless badly waterlogged, and there are species suitable for sunny and shady spots in the garden. However the smaller species tend to need sun and free-draining soil. The taller varieties are better placed towards the rear of the border with lower growing plants towards the front. There are even Geraniums suitable for the rock garden.
Feed monthly with a balanced fertiliser, such as growmore, through the growing season.
Most Geraniums can tolerate periods of drought but shouldn't be allowed to dry out. If your garden enjoys hot, sunny conditions then your plants may appreciate some light shade. Some species actually prefer shade.
If you cut back your plants to near ground-level after flowering, you may enjoy a second burst of flowers.
Some varieties have foliage which looks unkempt by the middle of summer, but cutting them back hard with shears will encourage production of fresh foliage. Give them a dose of tomato feed or similar to complete the job.
Most Geraniums are easily propagated by division, either in spring or autumn, or you can take root cuttings after flowering has finished. Many species can be easily grown from seed while some self-seed easily and spread quickly, making them ideal for a wild garden.
Geraniums can be attacked by slugs, snails and vine weevil larvae though it isn't usually a serious problem. If conditions get particularly dry they may suffer from powdery mildew but adding mulch in spring to keep the soil moisture content up should prevent this.
Here are some Geraniums recommended by the RHS which you might like to consider:-
Geranium 'Mavis Simpson' Low and spreading with lobed silvery foliage and pink flowers with dark veins. Flowers from June to October. 20cm (8in)
Geranium 'Renardii' Enjoys some of the loveliest foliage of all hardy geraniums, with broad lobed greyish leaves. Has sprays of white flowers with deep purple veins in June and July. Dryish conditions bring out the best in the foliage. A compact plant suited to the front of a sunny border. 35cm (14in)
Geranium 'Dilys' Excellent for ground cover, the purple-veined magenta pink flowers open from July until a hard frost. 'Dilys'will happily tolerate poor drainage and enjoys part shade as well as full sun, but is not suited to dry conditions. 40cm (16in)
Geranium 'Ann Folkard' Excellent for ground cover and also works well as a climber, with bright golden new foliage turning greenish gold later. It's dark-centred magenta flowers open in summer and continue into autumn. 50cm (20in)
Geranium 'Orion' Has large blue flowers with a hint of lavender and purple veins which are on display in large numbers all summer. Another excellent choice for ground cover. 75cm (30in)
Geranium pratense 'Mrs Kendall Clark' Flowering through June and July, it's pale blue flowers have a network of white veins and if dead-headed will come again for a second show. It has attractive foliage in spring. 90cm (3ft)
Every garden should have room for at least one of these excellent plants, and with new varieties appearing every year it will be even harder to decide which one it is.
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