Chrysanthemums are widely admired ornamental plants, celebrated for their diverse forms and colors. While these flowers come in various shades such as white, yellow, pink, red, and purple, the existence of a true blue chrysanthemum often sparks curiosity. The vibrant blue hue, a rarity in the plant kingdom, has led to innovative approaches in floral cultivation. This exploration delves into the scientific basis behind the absence of natural blue chrysanthemums and the methods employed to bring this sought-after color to life.
The Natural Absence of Blue
True blue chrysanthemums do not occur naturally due to a specific genetic limitation. The blue pigment in many flowers, known as delphinidin, is produced through a complex biochemical pathway requiring the enzyme flavonoid 3′,5′-hydroxylase (F3′5′H). Chrysanthemums lack the F3′5′H gene, preventing them from synthesizing delphinidin-based anthocyanins. This genetic deficiency explains why their natural palette is limited to shades like red, magenta, yellow, or white, despite centuries of traditional breeding efforts.
How Blue Chrysanthemums Are Achieved
Since natural blue chrysanthemums are not found, two primary methods are used to achieve this color: dyeing and genetic engineering. Each approach offers a different level of permanence and availability to consumers.
Dyeing
Dyeing is the most common method for commercially available “blue” chrysanthemums. White or cream-colored chrysanthemums are used for this process. The cut flowers absorb colored water through their stems, which travels up to the petals, imparting a blue hue. This method is temporary, and the blue shade will gradually fade.
Genetic Engineering
Genetic engineering offers a more permanent solution for creating blue chrysanthemums. Researchers have successfully introduced genes from other blue-flowered plants, such as the Canterbury bell or butterfly pea, into chrysanthemums. This allows chrysanthemums to produce delphinidin, the blue pigment. For example, Japanese researchers created a blue-violet chrysanthemum by introducing the F3′5′H gene and the A3′5′GT gene (anthocyanin 3′,5′-O-glucosyltransferase). While this method results in a stable color, genetically engineered chrysanthemums are not widely available to the general public due to regulatory and commercial factors.
Caring for Your Blue Chrysanthemum
Caring for chrysanthemums treated to appear blue primarily involves practices suitable for cut flowers. When you acquire a dyed blue chrysanthemum, proper hydration is important. Place the stems in a clean vase filled with fresh tap water. Adding flower food helps prolong the bloom’s life, and you should change the water every two days to inhibit bacterial growth.
To maximize water absorption, re-cut about 1 to 2 inches from the bottom of the stems at a 45-degree angle before placing them in the vase. Remove any leaves that would fall below the waterline to prevent decay, which can contaminate the water and shorten the flower’s lifespan. Chrysanthemums thrive in bright, well-ventilated areas, but they should be kept away from direct sunlight, drafts, and heat sources like radiators. Avoid placing them near ripening fruits or vegetables, as these can release ethylene gas, which accelerates wilting.