Annuals Dictionary: Pelargonium
Geranium family
Geraniaceae
Pee-lar-go’ni-um. Garden Geranium ; Stok’s-Bill Geranium . A large genus of 250 species of South African herbs and shrubs, their habits being very diverse.
Description
Stems strong-growing or trailing, herbaceous or woody. Leaves alternate, stalked, simple, entire and roundish, or much cut and often fernlike, some deeply marked on the upper side, a few fragrant. Flowers showy, irregular, ranging from pure white to pink, crimson, and bright scarlet, in umbel-like clusters growing on leafless stalks from leaf axils. Calyx of 5 sepals joined at the base. Petals 5. Stamens 10.
How to Grow
Start seeds indoors in late winter or early spring. Bottom heat of 70-75° F (21-24° C) helps seeds sprout in 14-21 days. Start early so that plants will have flower buds when planted outdoors after frost. Although these are warm-weather plants, midsummer heat and humidity, especially in Deep South, can cause them to burn out and die. Direct seeding will not work.
Pelargonium – domesticum
Martha Washington Geranium ; Summer Azalea . To 18 in. (45 cm) high. Flowers 1-3 in. (4.0-7.5 cm) wide, white, pink, or red, 2 upper petals usually blotched darker. Needs cool nights. Tender perennial grown as a tender annual.
Pelargonium – hortorum
Zonal Geranium ; Fish Geranium . 1-3 ft. (30-90 cm) high. Umbels many-flowered and flat-topped. Flowers 2-2 in. (5-6 cm) wide, red, salmon-pink, white, coral, peach, and bicolored, some with double blossoms. Faint fishlike odor. This group of hybrids based on P. zonale and P. inquinans . Tender perennial grown as a tender annual.
Pelargonium peltatum
Ivy Geranium ; Hanging Geranium . Stems trailing to 3 ft. (90 cm) long. 5- to 7-flowered. Flowers 2-2 in. (5-6 cm) wide, white to deep rose, upper petals having dark markings. Many cultivars and hybrid derivatives are available. Tender perennial grown as a tender annual.