Pelargonium × hortorum

Tried and Trouble-free Recommended by 3 Professionals
Common Name: zonal geranium
Type: Herbaceous perennial
Family: Geraniaceae
Native Range: Garden origin
Zone: 10 to 11
Height: 1.00 to 3.00 feet
Spread: 1.00 to 3.00 feet
Bloom Time: Flowers freely
Bloom Description: Red, purple, pink, orange, white
Sun: Full sun to part shade
Water: Medium
Maintenance: Low
Suggested Use: Annual
Flower: Showy
Leaf: Evergreen
Tolerate: Rabbit, Drought

Culture

Winter hardy to USDA Zone 10-11. In St. Louis, grow as annuals directly in the ground or in containers that may be sunk to the rim in garden areas or in containers, hanging baskets or window boxes. In the ground, grow in average to organically rich, medium moisture, well-drained soils with a neutral to slightly alkaline pH. Water regularly throughout growing season. Best in full sun, but appreciates some light shade in the heat of the day. Promptly deadhead spent flowering stems to promote additional flowering and to maintain plant appearance. Pinch stems to prevent legginess and promote bushiness. Although plants may be overwintered indoors, many gardeners simply grow them as annuals and repurchase new plants each spring. F1 hybrids may be grown from seed, and are often available from nurseries in flats. If overwintering is desired, several options are available: (1) as a houseplant by bringing containers indoors in fall before frost and placing in a bright, sunny but cool window with reduced watering or (2) as a dormant plant by bringing containers inside before first frost and placing them in a cool dark corner of the basement or frost free area of a garage. Dormant overwintering is generally advisable in order to promote the most vigorous flowering the following season. Cuttings may also be taken from favorite plants in late summer for overwintering or in early spring from overwintered plants.

Noteworthy Characteristics

Pelargonium × hortorum, known as zonal geraniums, are typically grown in the St. Louis area as bedding or container plants where they grow in shrubby mounds to 1-3’ tall. Hybrids are available in both F1 seed varieties (single flower types that flower the first year from seed and come true from seed) and vegetative varieties (semi-double to double types that are propagated by cuttings). Flowers appear in clusters (umbels) atop long flowering stalks throughout the growing season. Flowers come in a wide range of colors, including various shades of red, purple, pink, orange and white. Rich, medium green, rounded to kidney-shaped leaves usually but not always have dark circular zonal bands which give rise to the common name. Zonal geraniums are complex hybrids which have P. zonale and P. inquinans as dominant parents.

Genus name comes from the Greek word pelargos meaning a stork. The fruit has a beak like a stork.

Hybrid name means pertaining to gardeners.

Problems

Zonal geraniums can be tricky to grow well in hot and humid summer climates with periodic hard rainfall such as the St. Louis area. Poorly drained soils inevitably lead to stem and root rots. Plants are susceptible to leaf spots and gray mold. Watch for whiteflies and aphids, particularly on indoor plants. Caterpillars may chew holes in the leaves. For more information see: Problems Common to Many Indoor Plants

Garden Uses

Group or mass in beds and borders. Edging along walks or paths. Containers, hanging baskets or window boxes.