Hardy Geranium (Geranium 'Gerwat' Rozanne) by Lena Wegner
Geranium 'Gerwat' Rozanne at the Heritage Garden
From May through October hardy geraniums form a beautiful ground cover in the Heritage Garden’s round bed located in the vegetable section of the garden. A Montmorency cherry tree anchors the center of the bed, but it is the blue/purple flowering geranium underplanting that catches the eye. When the geraniums start blooming in May the bulbs that brightened early spring in that bed have withered, but from then on until frost, a delightful blue geranium carpet covers the ground.
Hardy geraniums are herbaceous perennials that grow to a height of 1’ to 2’ feet and a spread of 2’ to 4’. They form clumps or mats which can spread 2 to 3 square feet in one season, suppressing weeds as they grow. The saucer-shaped flowers are a luminous blue/purple with white centers and striking veining; they have a long flowering period. The chartreuse leaves are deeply cut into 5 lobes, and are marbled with dark green; in fall they turn red.
The plants like full or part sun, well-drained soil, and average moisture. Fertilizing in spring can ensure the plant's stellar performance. It is sometimes recommended to cut the plants back in late summer to encourage reblooming, but ours bloom so profusely, uninterruptedly until frost, that cutting the plants back would simply destroy the beautiful flowers. Hardy geraniums attract wildlife. On a sunny, warm day we can observe swarms of bees over the bed.
The plants are low maintenance. Hardy geraniums are normally not bothered by diseases or pests, and deer and rabbits tend to avoid them due to the aromatic foliage.
Geranium ‘Gerwat’ Rozanne, the cultivar in the HG, has earned the RHS Award of Garden Merit and is a Great Plant Pick.