GERANIUM if you are looking for Pelargoniums, whose common name is Geranium click here
GERANIUM. Crane’s bill. Worldwide, temperate regions. This group is a good indicator of recent enthusiasm for flowering perennials. Not long ago, even reputable horticulturists used the name primarily to refer to the related genus Pelargonium, from southern Africa. Now there are dozens of species and hybrids of true Geranium, recognized and sought out enthusiastically by gardeners. These are mostly smaller, slender stemmed perennials with rounded, often dissected leaves and–unlike the pelargoniums—regular (wheel shaped) flowers. Colors include some vivid purples and blues and wild magentas, as well as more subtle shades. They have a variety of uses in the border, for small-scale ground cover and for containers and rock gardens, according to size and shape. Most are easily grown in sun or light shade and most soils, with moderate to regular watering. A few are even fairly drought tolerant, as described below. Hardy at least to 10oF (often 0o) except as shown.
‘Ann Folkard’. A showy hybrid of G. psilostemon (see below), making a 1-1½’ high mound. It has very large (to 6-8" broad) basal leaves, still more unusual for their gold shading when young. The flowers measure about 1½” across, with broad, vivid reddish purple petals and black centers and veining.
x cantabrigiense. Hybrids of G. macrorrhizum and G. dalmaticum. They make neat, low mounds or mats, with bright green 1-2" leaves. Flowering is heaviest in spring, but the plants are seldom out of bloom in our climate. As now distinguished in the trade, ‘Biokovo’, first selected in the wild, is a rather widely spreading cultivar with nearly white flowers, shaded pink at the centers. ‘Cambridge’ is more compact in habit and has clear pink flowers.
cinereum. This is my favorite of the hardy geraniums. It has a stout, almost woody rootstock, branched to form a tight hummock of evergreen shoots, with nearly round, shallowly cut 1" leaves. The 1" to 1½" flowers, sprinkled over the plant much of the year, have beautifully colored petals and black centers. G. c. ‘Ballerina’ has silky greyish green leaves and silvery pink blossoms with darker veining. G. c. variety subcaulescens has dark, bluish green leaves and blossoms of deep, glowing purplish red.
dalmaticum. A matting species with small, spicily fragrant leaves painted bright, shiny green. It is dressed in spring in dainty pink blossoms clustered on 4-6" stems. Plants should be lightly shaded except along the coast.
endressii ‘Wargrave Pink’. A compact plant making mounds 6-12" high and at least twice as wide. It has deeply lobed, light green leaves and bright pink 1" blossoms with darker veining borne from late spring to fall.
‘Frances Grate’. This plant was kindly identified for us by Robin Parer, missionary and sage of the geranium alliance, after being sold simply as G. incanum x robustum for several years. It is a vigorous, billowy mound, easily covering 6-10’ in a few years and valuable as a ground cover. Both stems and leaves have a pleasing silvery grey cast. The leaves are up to 3" across, so narrowly and attractively cut as to suggest giant snowflakes, and held on very long, slender stalks. The flowers are reddish purple in color, about an inch across, and presented in open, long-stemmed clusters. Thus far it has passed through 20oF unscathed, but its ultimate hardiness is uncertain. It is moderately drought tolerant.
harveyi. A South African species, normally under 1’ high but spreading to perhaps 2’ or more. It has long-stalked 3/4" leaves, deeply dissected in the manner of G. incanum. However, in this case they are grey both above and below. In summer it has a scattering of magenta flowers, smaller and lighter in color than those of G. incanum. It should be useful as a small-scale ground cover.
himalayense (grandiflorum) grows about 1’ tall, eventually making broad carpets. It has dark green, deeply parted leaves and abundant 1½" violet blue blossoms, borne at the shoot tips in summer. The so-called variety alpinum, evidently a horticultural rather than a botanical form, is smaller and more compact, with even larger flowers. ‘Gravetye’ is of similar size but has smaller, more deeply cut leaves. The flowers are shaded with reddish purple around the cream-colored centers. ‘Birch Double’ is distinguished by fully double flowers.
incanum is a widely spreading plant with a decidedly fluffy appearance. The stems and undersurfaces of the leaves are nearly white with silky hairs. The long-stalked leaves are about 1" across and completely and narrowly parted. Reddish purple flowers, each a little over 1" across, decorate the plant most of the year. It makes a beautiful ground cover, thriving in full sun and requiring only occasional to moderate watering when established. Hardy to 20oF. or a little less.
‘Johnson’s Blue’. A hybrid between G. himalayense (see above) and G. pratense, this has been the most sought-after geranium in recent years. It grows a little larger than G. himalayense but with basically the same habit and has similar, though more narrowly divided, leaves. Its chief attraction is a nearly constant succession of large blue-violet flowers from late spring to fall.
macrorrhizum is a robust species, making a broad mound up to 18” high. It has fragrant, hairy leaves up to 4” broad. Flowers are usually a little over 1” broad and vary in color from white to purplish red. ‘Album’ is any one of several white flowered clones. ‘Ingwersen’s Variety’ is distinguished by its light green, softly shiny leaves and soft pink flowers. ‘Purpurascens’ has deep purplish pink flowers. One of the easiest species to grow.
x magnificum. A robust perennial, typically up to 2’ tall, probably less in our current material, and eventually forming colonies several feet across. The leaves are up to 4" wide, shallowly lobed and conspicuously veined, and colored dark green above, paler beneath. The flowers are broad petalled, about 2" across in this unnamed clone, and close to violet in color.
palmatum (anemonifolium) grows 2-3’ high and gives a bold, tropical impression. Around the thick, upright stems are arranged very large (to 8" or more), five-parted and dissected leaves. These have a highly polished surface and are held on long, sturdy stalks. In the summer months clusters of 1-2" purplish red blossoms are carried at the branch tips. Sun or part shade near the coast, part shade inland (it combines beautifully with ferns in shady spots). Surprisingly drought tolerant, and hardy to around 20oF.
‘Phillipe (Phillippe?) Vapelle’. This is one of the best of our recent acquisitions. It makes dense clumps, slowly spreading to perhaps 2’. The leaves are nearly round in outline, shallowly lobed and textured like G. renardii, below. It seems to be nearly nonseasonal, displaying large lavender-blue flowers just above the foliage, intermittently from spring to fall. A well-behaved perennial, ideal for cramped quarters where the wandering tendencies of some geraniums would be unwelcome.
platypetalum. A rather dense mound or mat, growing a little over 1’ high. It has very dark, slender-stalked, broadly lobed leaves, 3-8" wide. Good quantities of 1-1½” flowers, blue-violet overall, with rosy centers, decorate the plant in the summer months (well into fall for us).
psilostemon. Turkey. One of the largest of the true geraniums, growing as much as 4’ high (though probably under 2’ in our current material). It has large, dark, deeply parted leaves which turn attractive red and orange shades in the fall. The flowers are 1" to nearly 2" broad and strikingly colored, deep magenta with black centers.
renardii. A tidy hummock or mat. Its short stems are closely set with broadly lobed, interestingly textured, greyish green leaves. Large, pale lilac blossoms with purplish red veining are sprinkled over the plant from late spring to fall.
x riversleaianum. This is a group of hybrids between G. endressii, a European species, and G. traversii, from Chatham Island near New Zealand. The plants are low and mounding, with densely packed basal leaves and slender, branched flower stems. ‘Mavis Simpson’ has grey-green leaves and bright to pale pink flowers (most vivid in cool weather) with lighter centers, about 1½” across. ‘Russell Prichard’ has bright to deep green leaves and stems and deep purplish red flowers, a bit over 1" across. Both selections flower throughout the summer and well into fall.
sanguineum. A trailing plant, about 6" high by perhaps 2’ broad in the plants we grow. It has attractive dark green, sharply lobed leaves, tinged with red in fall, and produces purplish-red 1½" blossoms throughout the summer months. ‘John Eisley’ is a selected form making a particularly low, dense mat. It produces a wealth of dark flowers. The variety striatum (aka lancastriense) is quite prostrate and relatively slow growing. It has pink flowers with darker veins.‘Album’ is a little larger and looser in habit than most. The flowers are also larger, and colored snow white with fine reddish veins.