Geraniums, with their incredible profusion of blooms, are one of the most recognizable and widely cultivated ornamental plants across the globe. These popular garden staples provide continuous, vibrant color throughout the warmer months, making them a fixture in window boxes, patio containers, and garden beds. Their extensive color palette allows gardeners to select from a rich array of hues to suit any design or location. This diversity has solidified the geranium’s reputation as a dependable source of bright, enduring floral displays.
Distinguishing the Two Types of Geraniums
The name “geranium” causes frequent confusion because it describes two separate types of plants belonging to the family Geraniaceae. The bedding plants most often seen in nurseries, known as “florist’s geraniums,” are actually members of the Pelargonium genus. These tender plants are typically grown as annuals and are the source of the intense, fiery colors that dominate summer displays. True geraniums, or “cranesbills,” belong to the genus Geranium and are hardy perennials that return year after year.
The flower structures offer a clear distinction. Pelargoniums display zygomorphic, or asymmetrical, blooms where the two upper petals differ from the three lower ones. Conversely, perennial Geranium species produce radially symmetrical flowers with five nearly identical petals. This botanical difference is reflected in their color ranges: Pelargoniums offer bold reds and oranges, while hardy Geraniums tend toward softer blues, purples, and whites.
The Core Spectrum of Geranium Colors
The most common hues are found within the Pelargonium genus, which includes the familiar Zonal and Ivy types. Red remains the quintessential geranium color, available in shades from brilliant scarlet to deep, velvety crimson. Cultivars like ‘Calliope Dark Red’ provide a rich, nearly black-red hue, while others lean toward an orange-red for a more fiery impression. The intensity of the red pigment, derived from anthocyanins, makes these blooms highly visible and a traditional choice for summer containers.
The pink spectrum is equally varied, moving from pale, delicate blush tones to vibrant magentas and hot pinks. Salmon and coral shades are highly sought-after, distinguished by a unique combination of pink with a subtle peach or orange cast. These warmer pinks, such as the ‘Rosalie Antique Salmon’ variety, offer a softer yet saturated alternative to the bold reds.
White geraniums serve as a refreshing contrast, ranging from the purest, crisp white to subtle creamy or pale ivory tones. Standard purples and lavenders are also prominent, often exhibiting a saturated, jewel-toned appearance. These violet shades, sometimes seen in varieties like ‘Americana Violet’, provide a depth of color that contrasts beautifully with the reds and pinks.
Uncommon Hues and Color Limitations
Beyond the standard palette, geraniums offer complex and patterned colors, particularly in the Regal or Martha Washington types. Many cultivars feature intricate bi-color patterns, such as blooms with a contrasting central eye, distinct streaks, or feathered edges. Some flowers exhibit a lighter color on the outer petal edges and a deep shade at the center, creating a striking halo effect. The deepest colors are often described as “black,” but these are technically intensely dark shades of maroon, burgundy, or reddish-black, where the pigment concentration is exceptionally high.
Variegation is another element that adds complexity, though it is usually a feature of the foliage rather than the flower. Cultivars like ‘Mrs. Pollock’ boast leaves patterned with green, bronze, and cream, providing color interest even when the plant is not in full bloom. The unusual ‘Starry’ series features star-shaped flowers with thin, pointed petals, which adds a unique form to the color presentation.
Despite this extensive range, specific color limitations are governed by the plant’s natural pigments. The popular Pelargonium types notably lack a true blue color, and any flower described as blue is typically a shade of violet or purplish-mauve. Similarly, while a few species of Pelargonium may rarely exhibit a pale yellow, a vibrant, true yellow is largely absent from the genus. Conversely, the perennial Geranium species are the primary source of true blue flowers, like the widely planted ‘Rozanne’, a color rarely found in the common bedding geraniums.