Gardeners are sometimes confused by the differences between hardy geraniums (the subject of this discussion) and annual geraniums, known as Pelargoniums. Annual geraniums (pelargoniums) come almost exclusively from South Africa and are not winter hardy in the Portland area. They are container plants and bedding plants.
Hardy geraniums, on the other hand, occur worldwide in temperate regions with representatives growing in Europe, North America, New Zealand and much of Asia. Geraniums are winter hardy (perennial) and can be used in a variety of gardening conditions from rock gardens to shady woodland gardens. Pelargoniums and Geraniums are both members of the family Geraniaceae, along with Erodium, commonly known as storksbill.
Geraniums are referred to as “cranesbills” because the plant’s fruit resembles a crane’s bill. The genus geranium has four hundred species and countless cultivars. However, not all geranium species are suitable for the garden as some are not hardy enough to survive winters outdoors in northern climates, while others are very weedy in nature.
Geraniums are known for the breadth of conditions they can tolerate, from full sun to dry shade, as well as the ease with which they can be grown. They are a favorite with bees with flower colors ranging from white, blue, purple and a multitude of pinks. In addition, many of the flowers have interesting variegation, veining and spotting.
Leaf colors range from green, green with dark markings, green with yellow markings, as well as brown. Geraniums can be fun and easy for any kind of gardener and garden condition. They can liven up a rock garden or add texture and color to a romantic rose garden. In addition, many work well in dappled shade conditions underneath deciduous trees. Some of our favorite species and varieties commonly found at Portland Nursery are discussed below.
Geranium phaeum ‘Samobor’
Geranium phaeum is known as dusky cranesbill. It is extremely hardy, can withstand dry conditions and is almost evergreen. The mass of leaves on this species form dense, vigorous mounds, making it excellent as a ground cover. Geranium phaeum ‘Samobor’ was found in 1990 near Croatia. The flowers are burgundy and the leaves are green with a broad black-red band. This variety can tolerate sun or shade and blooms in early summer.
Geranium macrorrhizum ‘Variegatum’
This species grows wild in southern Europe in the Alps and in the Balkans. The sticky, hairy leaves are more or less round and lightly indented. The plant smells distinctive and has been used for perfume and in tanning processes. Geranium macrorrhizum ‘Variegatum’ has magenta flowers and variegated leaves in yellow and green. This geranium can tolerate sun or shade and blooms in early summer.
Geranium ‘Johnson’s Blue’
This geranium is a hybrid that originated in Wales between G. himalayense and G. pretense. The flower color is blue-violet and it is tall and gorgeous during bloom with large flowers. Bloom time is early summer and it can tolerate sun or partial shade. The plant’s only weak point is that it can have a hard time remaining upright. However, it responds well to being cut back and will in turn respond with a new mound of green leaves and sometimes flowers.
Geranium ‘Ann Folkard’
This geranium prefers sun to partial shade and blooms in midsummer. Flower color is warm magenta-red with a black eye. This is a hybrid of G. procurrens and G. psilostemon. From G. procurrens the hybrid gets its long stems and from G. psilostemon it gets its shocking magenta-red flower and black eye. The leaves are yellowish green and provide a striking contrast with the flower color. It is worth noting that this geranium may be a bit sensitive to very cold and wet winters.
Geranium ‘Ann Thompson’
This geranium is a hybrid with the same parents as Geranium ‘Ann Folkard.’ The two are very similar to each other although ‘Ann Thompson’ has slightly smaller flowers, the foliage is less yellowish green in color and ‘Ann Thompson’ is slightly more compact. Unfortunately, similar to ‘Ann Folkard,’ Ann Thompson’ is sometimes not hardy and may suffer in a very cold, wet winter.
This is a hybrid between G. himalayense and G. wallichianum ‘Buxton’s Variety.’ The plant was introduced at the 2000 Chelsea Flower Show in London by Blooms of Bressingham after many years of attempted propogation. It tolerates sun to partial shade, blooms the entire summer, and has a flower that is deep blue with a hint of red, as well as a whitish center and black stamens. The plant is extremely vigorous and can put out stems that grow to three feet tall.
Geranium renardii ‘Tcschelda’
This geranium prefers full sun and well drained soil. Bloom time is early summer. Flowers of this variety are pale purple with purple veins. The petals of the flower do not sit close together which makes the flowers very distinctive. The leaves are very attractive, thick with fine hairs and grey green in color. This variety can be used in rock gardens or at the front of beds and flowers best in poor soil.
Geranium ‘Philippe Vapelle’
A Belgian cross of G. renardii and G. platypetalum, this hybrid was discovered in two locations in the wild and was first described in 1949. This hybrid has inherited the pretty foliage of G. renardii (grey-green with fine hairs) and the beautiful dark violet flowers of G. platypetalum.
Geranium x oxonianum
A hybrid of G. versicolor and G. endresii, this hybrid is noteworthy for its huge variety of flower colors (white, all shades of pink and burgundy) found in a number of cultivars. Known for blooming all summer in sun or partial shade this hybrid can be enjoyed in the garden from early in the year, when the plants form dense green mounds, until late autumn.
The varieties of Geranium x oxonianum have many uses in the garden as they tolerate some shade, grow quickly and are easy to propagate. They can also be used as a groundcover. In addition to the flowers, the leaves of this hybrid also show variation. Some varieties have a maroon patch, while in others the leaves are totally green. After the primary flowering in June, some may need cutting back, but they will soon be back on track with fresh leaves and new flowers. This hybrid is also known for being enormously fertile, thus producing many seeds. Some varieties that Portland Nursery has carried include ‘A.T. Johnson,’ ‘Claridge Druce,’ ‘Katherine Adele,’ and ‘Pearle Boland’ (pictured above).
FACTS: HARDY GERANIUM
Origin: Geraniums occur worldwide, mostly in temperate regions with representatives growing in Europe, North America, New Zealand and much of Asia.
Culture: Geraniums are equally happy in light, acidic, sandy soil, in clay or alkaline conditions. Geraniums are easy to grow and tough. They can tolerate a variety of conditions from full sun to deep shade.
Further, some prefer drier rock garden conditions, while others prefer more moist woodland conditions. There are, therefore, geraniums suitable for every type of gardening condition.
Pests and Diseases: Some varieties may suffer from mildew but this can be dealt with by cutting them back after bloom.
Maintenance: Care of geraniums is minimal. Organic matter such as compost is all that is needed for fertilizing. Also, the tallest plants can be cut back after flowering to prevent them from going to seed and looking tired.
Propagation: Many varieties of geranium can be propagated from seed and division.