Ground covers, Perennials
The common indoor/outdoor plant most people know as geranium is, botanically, Pelargonium. Considered here are true geraniums, which are mostly hardy plants. Many types bloom over a long period, bearing flowers that are attractive though not always as showy as those of pelargoniums. Carried singly or in few-flowered clusters, blossoms have five overlapping petals that look alike. (Pelargonium flowers also have five petals, but two point in one direction, while the other three point in the opposite direction.) Colors include blue, purple, magenta, and bluish rose; some are pure pink or white. Beak-like fruit that follows the flowers accounts for the common name “cranesbill.” Leaves are roundish or kidney-shaped, lobed or deeply cut; plants may be upright or trailing.
Good in rock gardens and perennial borders; some are useful as small- or large-scale groundcovers. A few shrubby species are good for holding slopes. Best climates for most geraniums are cool- and mild-summer regions, where the plants can grow in full sun or light shade. In hot-summer areas, give afternoon shade. South African species are less cold-hardy but are more tolerant of heat and afternoon sun. All species appreciate moist, well-drained soil.
Some geraniums benefit from being cut back after flowering or in the fall. Clumps of most types can be left in place for many years before they decline due to crowding; at that point, divide in early spring. Increase by transplanting rooted portions from a clump’s edge; or take cuttings. Many produce lots of seedlings, and some can become naturalized pests.Geranium sanguineum
Native from western Europe to the Caucasus and Turkey. Forms a dense clump 8–18 in. high, spreading by rhizomes to 2 1/2 ft. or wider. Dark green, 1–2-in.-wide leaves are deeply divided into five to seven lobes, each with three narrow segments; turn blood red in fall. Typical forms have deep purple to almost crimson flowers 1 1/2 in. wide; bloom late spring well into summer and will rebloom if cut to the ground.
Good 1–1 1/2-ft.-tall selections include white ‘Album’; ‘John Elsley’, pink with deeper pink veins; and reddish purple ‘Max Frei’.
G. s. striatum is a ompact subspecies that grows to only 5–6 in. high. Bears light pink flowers heavily veined with red (its seedlings may vary somewhat) and makes an excellent rock garden or foreground plant.
Deciduous, from Europe, North Africa, and central Asia. Grows to 8–15 ft. tall and wide, with ar...
Native from western Europe to the Caucasus and Turkey. Forms a dense clump 8–18 in. high, spread...
Native from central Europe to Siberia. To 1 1/2 ft. high, 1 ft. wide. Pale blue or white flowers ...