Rose petals come in a variety of colors, from the classic red to white, pink, yellow, orange, purple, and even blue or black. The color of a rose petal is determined by pigments called anthocyanins that are present in the rose’s cells. The specific type and amount of anthocyanins lead to the rich diversity of rose colors. Understanding rose genetics and breeding can help explain the science behind rose petal color.
Common Rose Petal Colors
Here are some of the most common rose petal colors and what makes them that hue:
Red
Red roses contain the anthocyanin pigments pelargonidin and cyanidin, which give them their bright crimson color. Red roses symbolize love, romance, and passion. They are a classic Valentine’s Day gift and the most popular color of rose.
Pink
Pink roses get their soft hue from lower levels of pelargonidin pigment. The less concentrated pigment leads to a lighter red or pink color. Pink roses symbolize gratitude, grace, and joy.
White
White roses contain no anthocyanin pigments. The lack of pigment results in a pure white color. White roses symbolize purity, innocence, and youthfulness.
Yellow
Yellow roses get their sunny color from carotenoid pigments like lutein and zeaxanthin. These yellow and orange pigments are what make corn and bananas yellow too. Yellow roses symbolize friendship and joy.
Orange
Orange roses contain moderate levels of carotenoids mixed with low levels of anthocyanins. This combination makes their warm, orangey hue. Orange roses symbolize enthusiasm, passion, and energy.
Less Common Rose Colors
While red, pink, white, yellow, and orange encompass most rose varieties, there are some other interesting rose petal colors out there:
Purple
Purple roses occur when red pigments combine with higher levels of blue/violet anthocyanins like delphinidin. The mix leads to a rich, royal purple color. Purple roses symbolize enchantment and love at first sight.
Lavender
Lavender roses have a lighter purple-gray hue from lower concentrations of anthocyanins. They symbolize love, devotion, and splendor.
Blue
Blue roses do not occur naturally, but can be made by dyeing white roses or using genetic modification. Blue represents the unattainable and impossible in flower meanings.
Black
Black roses are also an unnaturally created color, often by dyeing red roses. They represent death, farewell, and endings.
| Rose Color | Pigments | Meaning |
|---|---|---|
| Red | Pelargonidin, cyanidin | Love, romance |
| Pink | Low pelargonidin | Gratitude, grace |
| White | No anthocyanins | Purity, innocence |
| Yellow | Carotenoids | Friendship, joy |
| Orange | Carotenoids, anthocyanins | Enthusiasm, passion |
| Purple | Anthocyanins | Enchantment, love |
| Lavender | Low anthocyanins | Devotion, splendor |
| Blue | Dyed/modified | Unattainable |
| Black | Dyed | Farewell, endings |
Genetics of Rose Color
The diversity of rose colors comes down to genetics. Different rose species and cultivars contain varied amounts of the pigments that lead to red, pink, orange, yellow, and other hues. Here is an overview of the key genetic factors:
Anthocyanins
Anthocyanins are water-soluble pigments that give roses red, purple, and blue shades. Roses inherit different forms (alleles) of the genes that code for anthocyanin production, leading to higher or lower concentrations.
Carotenoids
Carotenoids like beta-carotene are fat-soluble pigments that create yellow, orange, and related colors. Different alleles control carotenoid levels in roses.
pH
The pH or acidity level of rose petal cells also impacts color. More acidic conditions make anthocyanins turn reddish, while less acidic conditions shift them blue.
Co-pigments
Other compounds called co-pigments can modify anthocyanins. Metals like iron increase bluing, while flavonoids intensify redness.
Genes
Key genes that control rose color include DFR (dihydroflavonol reductase) which regulates anthocyanins, PSY (phytoene synthase) which controls carotenoids, and many others.
Rose Breeding
Selective breeding has allowed the development of many new rose varieties with unique colors. Breeders cross roses with desired traits and select offspring with the colors they want. Common breeding methods include:
Hybridization
Crossing different rose species can introduce new color-controlling genes. Hybrid tea roses resulted from breeding European with Chinese roses.
sports
Spontaneous genetic mutations can make “sports” offshoots with new colors. These are cloned to make a new variety.
Genetic engineering
Adding or silencing genes can create new colors like true blue roses. But genetically modified roses are controversial.
Overall, centuries of rose breeding have yielded the rainbow of colors we enjoy today. Yet new gene discoveries enable ongoing creation of novel shades and hues.
Environmental Factors
In addition to genetics, some environmental factors can slightly alter the color of rose petals:
Light
Exposure to light increases production of pigments. Roses grown in more shade may have lighter, softer colors.
Temperature
Colder temperatures can boost anthocyanin levels, creating deeper colors. Warmer conditions lead to lighter pinks and reds.
Soil
Soil pH affects pigments. More alkaline soils facilitate blues/purples, while acidic soils boost reds.
Water
Drought stress triggers higher pigment production. Adequate water keeps colors vivid. Too much water can dilute shades.
Age
Pigments decline with age, so older roses may fade to lighter tones. Pick roses when fully open for deepest color.
Proper rose care optimizes color, but genetics are the main determinant of hue for a given variety.
Distribution of Color Among Rose Species
While most major rose colors occur across various species and hybrids, some tendencies emerge in distribution:
Red roses
Red is common across most roses but especially prevalent in hybrid teas, floribundas, and polyanthas.
Pink roses
Many hybrid teas, floribundas, grandifloras, miniatures, and polyanthas come in shades of pink.
White roses
White is frequent among hybrid teas, floribundas, old garden roses like albas, and shrub roses.
Yellow roses
Yellow occurs across types but is most common in polyanthas, hybrid teas, and David Austin English roses.
Orange roses
Orange is also found among hybrid teas, floribundas, polyanthas, and miniature roses.
Other colors
Less common colors like purple tend to be limited to novelty hybrids.
In general, modern rose classes exhibit the widest range of colors due to extensive hybridization and breeding.
Uses of Colored Roses
The stunning colors of roses make them ideal for:
Floral arrangements
A mixture of colored roses creates beautiful, eye-catching bouquets and centerpieces.
Garden displays
Planting a variety of rose colors provides vibrant garden interest.
Special occasions
Red and pink roses are given as symbols of love and appreciation.
Home decor
Vases of colorful roses brighten up indoor spaces.
Cosmetics
Rose petals and extracts add tint to lotions, makeup, and perfume.
Cooking
Some roses like Rosa rugosa have edible petals that add flavor and color to food.
Medicinal use
Many cultures use rose petals for their therapeutic effects.
Conclusion
In summary, rose petal color stems from specialized plant pigments whose production is controlled by flower genetics. Breeding has yielded an incredible array of hues across rose species and cultivars. Rose colors result from complex interactions between numerous genes and growing conditions. The stunning palette of tones makes roses universally admired as symbols of love, beauty, and joy. With improved knowledge of color-determining factors, we can anticipate even more diverse shades in future rose hybrids.
