The genus Delphinium, commonly known as Larkspur, comprises hundreds of species of flowering plants celebrated for their striking, towering spires. These hardy perennials are a staple in garden borders, creating a dramatic vertical element with their densely packed florets. The color spectrum is wide, yet defined by genetic limitations that govern the hues available. Cultivated varieties reveal a palette dominated by specific families of color.
The Signature Hues (Blues and Violets)
Delphiniums are famous for producing one of the few true-blue colors found in the plant kingdom. This pigmentation is derived from delphinidin, a type of anthocyanin responsible for blue and purple tones. The exact shade of blue is often influenced by the flower’s pH level, with a more alkaline environment favoring bluer tones.
Within this signature range, cultivars span a spectrum from delicate sky blue to deep indigo. Varieties are described as cobalt blue, sapphire, or near-navy, often distinguished by a contrasting “bee” or center, which can be white, black, or brown. Popular hybrid series, such as the New Millennium and Pacific Hybrids, offer deep violet and purple blossoms like ‘King Arthur’ and ‘Black Knight’. These blue and violet flowers provide a rich, cool-toned foundation for perennial garden designs.
The Expanding Palette (Pinks and Whites)
While blue is dominant, the available colors expand into the lighter end of the spectrum, including pinks and pure whites. White delphiniums, such as the cultivar ‘Galahad,’ brighten shaded areas and serve as a crisp accent against deeper blues. These white flowers often possess a creamy or ivory tone, rather than a harsh white.
Pink shades range from the palest blush to a richer, rosy hue, sometimes carrying a subtle lavender undertone. Cultivars like ‘Guinevere’ showcase lavender-pink, while ‘Pink Punch’ offers a soft rosy-pink. The presence of pinks and whites is the result of differing pigment ratios, where the blue-producing delphinidin is either absent or present in very low concentrations. These lighter tones offer a softer contrast to the dominant blues and violets.
Colors That Do Not Exist
Despite the wide array of colors, the Delphinium genus notably lacks certain vibrant, pure colors common in other flowers: true reds, oranges, and deep yellows. The genetic pathways that produce necessary pigments, such as carotenoids for vibrant yellows and specific anthocyanin derivatives for true red, are absent in most garden hybrids.
While modern breeding introduced cultivars described as coral-red, such as ‘Red Lark,’ this color is a deep salmon or watermelon shade, not a primary scarlet red. This hue is derived from a cross using species like Delphinium cardinale, which naturally carries a reddish-orange pigment. Similarly, a true, vibrant yellow is rare, often appearing as a pale or sulphur yellow. This yellow is sourced from Delphinium zalil, which is not easily bred with common garden varieties, resulting in a subtle hue.