Clematis are popular climbing vines known for their spectacular blooms that add vertical interest to gardens. The genus includes over 300 species and thousands of cultivars, offering remarkable diversity in flower size, shape, and color. Clematis produces flowers across nearly the entire color palette. The specific hue is determined by its genetic makeup, but the intensity of the color can be influenced by external growing conditions.
The Full Spectrum of Hues
The most common and celebrated colors in clematis are the deep purples and blues, which offer a wide spectrum of shades. Purple varieties range from the nearly black, velvety blooms of deep royal purple cultivars to soft, misty lavenders and mauve tones. Blue flowers can appear as vibrant, true sky-blue shades or as a more powdery, periwinkle blue, often depending on the cultivar’s genetic tendency toward reddish or bluish pigments.
Clematis also boasts a substantial collection of flowers in the red and pink family. Red cultivars span from bright, almost scarlet hues to rich, deep burgundy or wine-red blooms. Pink varieties include delicate, blush-pink pastels and vibrant, saturated magentas or hot-pinks. White clematis provide a classic contrast, appearing either as pure, stark white or possessing warmer undertones, such as creamy white or pale ivory.
Although less common, yellow clematis varieties do exist, typically belonging to species like Clematis tangutica. These blooms often present as bell-shaped, nodding flowers in shades of bright lemon-yellow or golden-yellow. This extensive color range ensures a clematis variety is available for nearly any garden design.
Patterned and Multi-Toned Varieties
Beyond solid colors, many clematis cultivars display complex, multi-toned patterns. Bi-color varieties feature sepals of two distinct colors, creating a striking visual effect. A common pattern is the contrasting “bar,” which is a stripe of a different color running down the center of each sepal. For example, the popular ‘Nelly Moser’ showcases pale lilac sepals with a carmine-pink bar down the middle.
Other varieties feature a picotee edge, where the outer margin of the sepal is a contrasting color to the main body. Color complexity also comes from the stamens and anthers at the flower’s center. Many blooms have sepals of one color, such as white or pink, but possess a contrasting center formed by a cluster of deep red, reddish-purple, or bright yellow anthers.
How Environmental Factors Affect Color
The shade and intensity of a clematis flower can be modulated by its growing environment. Sunlight exposure is a major factor, particularly for darker purple, blue, and red cultivars. Intense, direct sunlight can cause pigments to degrade, leading to “sun bleaching” where the color appears faded. Conversely, planting blue and purple varieties in partial shade often results in a deeper, more saturated color because lower light levels help preserve the anthocyanin pigments. The age of the bloom also plays a role, as the color of some varieties will naturally shift over time.