Common Geranium, Zonal Geranium, Bedding Geranium, or Geranium

(Geraniaceae - Geranium Family)

• Form
  • small- to medium-sized herbaceous annual
  • mature size ranges from 12" to 18" tall and 18" to 24" wide, depending upon cultivar
  • spreading mound growth habit

• Culture
  • full sun to partial sun
  • prefers a moist, well-drained soil in full sun, with a light mulch covering the soil to cool the root zone
  • propagated either by seeds or rooted stem cuttings
  • Geranium Family, with a number of significant disease (leaf spot, black leg, blight, root and stem rots, rust) and pest (mite, mealybug, caterpillar) problems, the most significant of which is Botrytis blight
  • abundantly available in flats, containers, hanging baskets, or seed packets
  • dead-heading of spent inflorescences allows for continuous bloom throughout the Summer
  • although Common Geranium diseases and pests are usually not severe in outdoor situations, they can often be minimized by a combination of cultural practices, namely:
    • not planting too densely (allowing sufficient air flow to dry the plants from rain, irrigation, and dew)
    • not overwatering, and avoid splashing the foliage with water when irrigating (such as by using trickle or soaker hose irrigation, or letting the watering hose run on the bed area)
    • removing infected plants (or plant parts) upon notice of pathogens, and spraying afflicted plants upon notice of pests
    • practicing crop rotation from one year to the next (i.e., do not plant Geraniums in the same location year after year)
    • removing freezed-killed plants in mid-Autumn, and overturning the soil in Autumn for exposure to Winter freeze/thaw cycles

• Foliage
  • leaves are 3" to 5" across, medium to dark green, cordate in shape, bold-textured, thick, and oppositely arranged on the thick upper stems, but very clustered at the base of the low-branching plant
  • leaves have three to five shallow lobes with very crenate margins, with the plane of the leaf blade not flat, but cupped at the cordate base, causing water to pool at the bottom of the leaf blade that joins to the top of the 5" long thick petiole
  • leaves are sometimes "zoned" with a dark bronzed band halfway down the leaf blade and parallel to (i.e., equi-distant from) the leaf margin
  • foliage is somewhat pubescent, and exudes a strong fragrance or odor when bruised, but not nearly as pungent as other Geranium hybrids that are grown for their scent

• Flowers
  • white, pink, red, salmon, orange, violet, and all shades in-between, with bicolors and double flowering forms also available
  • flowering from June until frost, in large showy spherical clusters atop long stiff peduncles, with continuous bloom strongly encouraged by frequent dead-heading
  • inflorescences are bold-textured due to their size, shape, and being held well above the foliage, and are found in either single-colored plantings or mixed-color plantings

• Fruits
  • the fruits are needle-like projections that radiate from the fruiting head; however, the spent flowers are unnattractive and should be dead-headed as often as possible, to encourage continuous bloom

• Twigs
  • stems are thick, much-branching at the base of the plant, and acquire prominent (but hidden) leaf scars as the lower foliage (with its swelled petiole base) abscisces from self-shading and senescence

• Trunk
  • not applicable

• ID Summary
  • large spherical showy inflorescences rise above the dense, cordate, green and zonally bronzed foliage, with thick stems and a scented odor from the foliage when it is bruised

• Function
  • frequently used as a bedding plant for group or mass plantings, foundations, entranceways, pathways, and borders
  • also commonly used as a bold-textured accent in urns, hanging baskets, window boxes, planters, and even as an indoor plant in Winter

• Texture
  • bold texture
  • average to thick density

• Assets
  • Summer-long bold-textured flowering (especially when frequently dead-headed)
  • wide range of floral colors, in single or double flowers
  • lush foliage is dense, medium to dark green, and often bicolored (with a bronze zonal band)

• Liabilities
  • inflorescences need to be dead-headed repeatedly after heavy bloom or a strong rain, to remove the unnattractive spent inflorescences and to promote continuous bloom
  • several diseases and pests can significantly affect the foliage and floral quality, especially during rainy periods in mass plantings
  • leaf tip browning in hot, dry weather

• Habitat
  • annual that dies with several frosts or the first hard freeze
  • Common Geranium is of complex hybrid origin from several Geraniums, but most species are native to South Africa

• Alternates
  • Summer-flowering annuals with prominent foliage (Begonia x semperflorens-cultorum, Coleus x hybridus, Senecio cineraria, etc.)
  • Summer-flowering annuals with bold-textured, large floral heads (Celosia [crested types], Cleome x hasslerana, Tagetes erecta, etc.)

• Variants
  • many series and cultivars exist, based upon plant compactness, earliness to bloom, consistent bloom, floral color or bicolor, single or double flowers, inflorescence openness versus density, and bronzed leaf zonation

• Translation
  • Pelargonium translates from the Greek word pelargos as "stork", again due to the similarity in shape of the fruits to a stork (or crane's) elongated beak.
  • x hortorum translates as "of gardens" and refers to its domesticated usage as a complex hybrid.
  • Geranium, the common name, translates from the Greek word geranos as "crane", due to the similarity in shape of the seldom-noticed fruits to a crane's (or stork's) elongated beak.
  • Perennial Geraniums (not discussed here) belong to the genus Geranium, most species of which are cold-hardy throughout temperate zones, while Common Geranium (discussed herein under the genus Pelargonium) is an annual in all but tropical regions.

• Purpose
  • Common Geranium is a very popular annual for usage in beds and containers.

• Summary
  • Pelargonium x hortorum is a common annual noted for its bold-textured clusters of floral heads, blooming all Summer long atop its dense, medium to dark green, and often zonally-bronzed foliage.