Cranesbills are not only hardier than Pelargonium "geraniums," but also tolerate shade better. The hardy geranium flowers are symmetrical, carried singly or in clusters of two or three, with five overlapping petals that look alike. (Pelargonium flowers have five irregular petals, with two pointing in one direction and three pointing in the other direction.) Geraniums bloom over a long period during summer, with colors including rose, blue, purple, pink or white.

The flowers are followed by long beaked seedpods that split suddenly when ripe. The seed is expelled upwards and outwards, resulting in seedlings sometimes popping up in rather unexpected places.

Geraniums are native to Europe and Asia with over 300 species widely distributed over temperate regions and the lower vegetation belt of mountainsides in the tropics. These plants provide a long period of summer flowers in a wide range of colors. They mix well with all kind of plants. There's at least one variety that will fit any garden, whether small or large, sunny or shady, dry or damp.

Wild geraniums were used by North American Indians and early settlers as an herbal remedy, being both safe and effective. The Chippewas used the rhizome, or underground stem, for sores inside the mouth, and other Indian peoples steeped the plant in water to use as an eyewash. Indians also ate the young green leaves as food. Cranesbill was listed in the U.S. Pharmacopoeia from 1820 to 1916. To this day herbalists recommend the plant for many of the same medicinal purposes, with the fluid extract and powdered rhizome both widely available in herbal stores.

Examples

There are many species and cultivars of geraniums that fit into three main groupings: tall varieties, low-growing, and wild geraniums.

Tall Varieties
G.endressii 'Johnson's Blue' is an immensely popular geranium, growing about 18-20" tall. Dark-veined mid-blue flowers, fading to pearl gray, smother the mounded plants in early summer and bloom intermittently until fall frost. It has finely divided foliage, with a rather sprawling habit that works best when allowed to make a dense clump of ground cover.

G. Brookside is a hybrid of G. pratense and G. clarkei 'Kashmir Purple' with sapphire-blue flowers all summer long that have pink veins and pale central eyes. It grows about 18' tall, with a mature spread of 23-27', and has a mounded habit with dark green foliage. It needs to be cut back in early summer for repeat bloom in fall. 'Brookside' is drought tolerant, doing well in full sun with some shade in the afternoon. It has lovely fall colors of orange and red.

G. endressii Wargrave Pink is another popular tall geranium. It has pink flowers with darker veining. The foliage is slightly fuzzy and semi-evergreen.

Low-growing Varieties
G. cincreum grows to 6” tall, much wider, and has dark green leaves. The 1” flowers are pink with darker veining blooming in late spring and summer. ‘Ballerina’ has lilac pink flowers with purple veining, ‘Lawrence Flatman’ has slightly larger flowers with a deeper color, and G. c. subcaulescens has deep purplish flowers with black centers with small scalloped leaves.

Geranium x cantabrigiense ‘Biokovo’ grows 6-8” in height and spread with white blooms tinged with pink and pink stamens. The overall effect is that of a very pale pink geranium on a plant forming a loose carpet of foliage. It blooms in May and June. This is a naturally occurring hybrid that was discovered in the Biokovo Mountains in Croatia.

Geranium macrorrhizum forms colonies of handsome semi-evergreen foliage with showy flowers that have a calyx in contrasting color to the petals. ‘Walter Iingwersen’ has soft pink blooms, album has white.

Geranium sanguineum is among the most heat tolerant, flowering early in the summer and right on into the fall, with pink flowers having rose veining. It forms a dense carpet of foliage.

Wild Geraniums
Geranium maculatum has several common names such as Alumroot, Dovefoot, Old-Maid’s Nightcap, Shameface, Chocolate Flower, or simply Wild Geranium. It grows up to 2’ tall and has hairy stems. The leaves are arranged in opposite pairs, usually divided into fine toothed lobes. The pale pink to rosy purple flowers appear from April to June.

There are other species of wild geraniums, but most are annual or biennial.

Special Features

This is a great plant for beginner gardeners. It is easily grown, long-lived, and very disease and deer resistant. Bees and butterflies are attracted to geranium blooms, and the leaves provide food for the larvae of some Lepidoptera species, including Brown-tail and Mouse Moth.

The plants work well in containers, for cottage gardens, in borders and mass plantings. Geraniums have flexible stems that make great “weavers” to fill in and around taller or stiffer plants. It is a good accent plant in sunny borders and rock gardens.

Geranium also works well as a ground cover, with G. macrorrhizum best for this purpose as it spreads by underground rhizomes and eventually forms an impenetrable mat that suppresses most weeds.

The wild geranium, G. maculatum, is used as an external astringent and a hemostatic (an agent that stops bleeding). and is reported to be effective when taken internally for diarrhea..

Hardiness

Geraniums are reliably hardy to –20° F.

Growth Habit

Geraniums range from the low-growing varieties that work well in the front of the border or as ground cover, to the taller, more upright varieties. They grow moderately quickly into a mound of foliage with roundish or kidney-shaped leaves that are lobed or deeply cut. The leaves are usually 1-2” wide, and turn red or orange after frost. There are often scattered hairs on the leaves and flower stems, and many are scented.

Bloom Time

Some geraniums bloom in mid-spring, some like G. endressii bloom in late spring, and others have a heavier bloom in early summer, then bloom intermittently through the rest of the season until frost. In warmer climates, some go dormant when the weather gets hot in July and August. The longest bloom period occurs in cooler zones of 6 and above.

Propagation

Geraniums seldom need division, but they can be propagated in that manner. They can also be grown from tip or root cuttings. Some geraniums are self-seeding, and of course, can also be grown from seed sown by the gardener.

Division is usually done in spring or fall. Some varieties pose problems because the stems tend to go back to a small rootstock. In that case, cuttings or seed may work better.

To divide a plant, cut the stems back to the ground and remove some of the topsoil around the base of the plant. Dig up the entire clump of roots, leaving as many roots as possible intact when the plant is lifted from the ground. Geraniums have a fibrous root system, so use your fingers to pull the clumps apart. Once the clump is divided, discard the tough, old roots and crowns from the center, and replant the younger outer sections.

Do not allow the clumps to dry out. Replant immediately at the same depth they were growing previously. Keep the soil evenly moist for the next several weeks until the new plants are well established. Mulch the divisions in late fall after the soil freezes, to keep the roots from heaving during the winter.

Germination or Cuttings

Germination Seed can be bought from several suppliers, such as Thompson & Morgan, or gathered from plants in the garden. If collecting seed, the pod must be watched closely so as to catch the seed before the pod bursts. Usually the pod changes color from green to brown. If uncertain when the seed will be ready, place a paper bag over the pod to be sure the seeds are collected when the seed pod bursts.

Germination of geranium seeds can be erratic, so it may take a long time for seedlings to appear. Some species require stratification of the seed before germination can take place.

Seed should be sown in pots or trays of moist seed compost and covered with a fine sprinkling of compost or vermiculite. Place the tray or pot in a bag and keep at the temperature of 60-68°F (15-20°C) until seedlings appear, or for 8 weeks. If no seedlings appear within that time, place the bagged container into a refrigerator (not freezer) for 3 weeks, then back to 60-68°F.

Once the seedlings have pushed through the soil, remove the bag and place the tray or pot in a well lit, well ventilated place at the temperature of 55-60°F (12-15°C).

Cuttings Geraniums with trailing stems can be propagated by spring cuttings using the new side shots. Semi-ripe cuttings may also be taken in summer. Remove each cutting above a node, where the leaves are attached, and cut about 1” off the bottom to leave a bare stem. Push the stems into soil in pots or trays, water in, the cover with plastic. Place in a shaded greenhouse, cold frame, or under lights until the cutting is well-rooted and growing.

Root cuttings can be taken when the plants are dormant. Dig the plant up and cut off a couple of sturdy roots 1/4 to 1/2 inch in diameter and 2-3 inches long. It helps to include some small, fibrous lateral roots. Place the root in loose soil with about 1/2 inch soil on top of the cuttings and 3-4 inches of soil underneath them. Keep the soil evenly moist. These cuttings can be kept in an insulated cold frame, in an unheated but frost-free basement or garage, or indoors under lights.

Transplanting

When seedlings are large enough to handle, they should be placed in bigger pots or trays with more room for growth. When well rooted and big enough to plant outside, the plants should be gradually acclimated to outdoor conditions for 10-15 days by placing them in a cold frame or outside in a shady, sheltered part of the garden. Spring and autumn are ideal times for transplanting, but it can be done anytime. Plant singly or in groups, with 24” between each plant. Water them well after planting.

Soil

Geraniums thrive in moist soils, especially in hot climates. It should be well drained, however. They thrive in soil with average fertility. Peat moss, compost or well-rotted manure is a good addition in moderate amounts. If the soil is too rich, it will encourage rampant growth.

Irrigation

Water the plants regularly, but do not allow to become waterlogged. They are fairly adaptable to short periods of dry conditions once established.

Sunlight

Plant in full sun or light shade. Afternoon shade is preferable, and helpful in warmer climates. G. sanguineum tolerates sun even in hot summers.

Care

Geraniums are an easy care plant, but there are a few things that can be done to promote optimum performance.

Mulch is helpful to maintain cool, moist soil. Remove spent blossoms after early summer bloom to encourage a repeat bloom period. If bloom dwindles, cut back stems to encourage repeat flowering from new growth.

Most species die down in autumn. Cut the old foliage and stems halfway down at that time, then almost completely to the ground in early spring. This encourages bushiness and a dense flower cover.

Geraniums may be left undisturbed for many years before they become overcrowded.

Pests

These plants are almost pest free. It is possible the Asiatic garden beetle, four-lined plant bug, or spider mites may affect some types.

Disease

Geraniums are generally disease free, but may occasionally fall victim to leaf spots, black root rot, rusts, mosaic virus, or fungus.

Additional Info

When buying geraniums, look for plants with plenty of leaves and shoots growing from the base, as this indicates a healthy, well-grown plant.

Refernces

Fell, Carolyn & Derek (1995). Step-by-Step Sun Gardening. Harrison, OH. Springhill Nurseries.

Southern Living. (1998) The Southern Living Garden Book. Birmingham, AL. Oxmoor House, Inc.

Reader’s Digest. (April 1983) Illustrated Guide to Gardening. Pleasantville, NY. The Reader’s Digest Association, Inc.

Brooklyn Botanic Garden. Bush-Brown, Louise and James (1996) America’s Garden Book. New York, NY. Macmillan.

Mulligan, William C. (1992) Rare and Unusual Plants. New York, NY. Simon & Schuster

Paul, Inge H. (1987) Wild Flowers of North Alabama. Huntsville, AL. Desk Top Publishing.

Reader’s Digest (1986) Magic and Medicine of Plants. Pleasantville, NY. The Reader’s Digest Association, Inc.

Halpin, Anne (1996) Horticulture Gardener’s Desk Reference. New York, NY. Macmillian.

Macunovich, Janet (1996) Caring for Perennials. Pownal, Vermont. Storey Communications, Inc.

Rodale Press (1976) Herb Book. Emmaus, PA. Rodale Press Book Division.