Nature’s palette is ever-changing, and nowhere is this more evident than in the world of flowers. Imagine a garden where blossoms transform before you, shifting from pristine white to blushing pink or from sunny yellow to fiery red. But what causes these mesmerizing transformations, and how do they benefit the plants?
From the famous hydrangeas that alter their hue based on soil pH to the enchanting “Yesterday, Today, and Tomorrow” plant that cycles through three colors in as many days, these botanical wonders offer a mesmerizing display of nature’s ingenuity.
But the show doesn’t stop there—each of these 13 flowers has a unique story and strategies for thriving.
1. Hydrangea macrophylla
Big-leaf hydrangeas are perhaps the most famous color-changing flowers. These stunning shrubs can produce blooms in shades of pink, blue, or purple, depending on the soil pH1.
Hydrangeas produce blue flowers in acidic soils with a pH below 6.0. As the soil becomes more alkaline, with a pH above 7.0, the flowers shift towards pink.
This remarkable ability is due to aluminum ions in the soil. Acidic soils make aluminum more available to the plant, resulting in blue pigments.
Gardeners can manipulate hydrangea colors by adjusting soil pH, adding lime to encourage pink blooms, or aluminum sulfate for blue flowers.
Some varieties, like the ‘Endless Summer’ hydrangea, are particularly adept at changing colors throughout the growing season.
2. Lantana camara
Lantana flowers are known for their multicolored clusters that change hue as they mature. These heat-loving plants typically start with yellow or orange blooms that gradually shift to pink, red, or purple.
This color transformation occurs within individual florets, creating a stunning display of shades on a single plant.
The lantana’s color-changing ability serves an important ecological function. Newly opened flowers, typically yellow, signal pollinators that they’re full of nectar.
As the flowers age and change color, they indicate to insects that the nectar supply has been depleted, encouraging pollinators to focus on the fresher blooms.
This clever strategy ensures efficient pollination and makes lantana an excellent choice for attracting butterflies and hummingbirds to the garden.
3. Hibiscus mutabilis
Also known as the Confederate rose or cotton rosemallow, Hibiscus mutabilis is famous for its color-changing flowers. These large, showy blooms open in the morning as pure white.
As the day progresses, they gradually turn pink, deepening to a rich rose color by evening. This daily transformation has earned the plant the nickname “cotton rosemallow.”
The color change in Hibiscus mutabilis is thought to be triggered by exposure to sunlight and temperature fluctuations. This unique characteristic makes it a fascinating addition to any garden, providing visual interest throughout the day.
This deciduous shrub can grow large in warmer climates and become a stunning focal point with its ever-changing blooms from late summer through fall.
4. Brunfelsia pauciflora
Commonly called “Yesterday, Today, and Tomorrow,” Brunfelsia pauciflora is a shrub that lives up to its poetic name. The flowers of this plant open in a deep purple color. Over three days, they fade to lavender and finally to white.
The plant displays blooms in all three colors simultaneously, creating a captivating ombre effect.
This color-changing process is not just for show – it serves an important biological function. The changing colors signal to pollinators which flowers are freshly opened and rich in nectar (the purple ones) and which have already been pollinated (the white ones).
This efficient system ensures that pollinators focus on the newer blooms, maximizing the plant’s reproductive success.
5. Quisqualis indica
Known as the Rangoon Creeper or Chinese Honeysuckle, Quisqualis indica is a vigorous climbing vine with fragrant flowers that change color. The blossoms open as white in the evening, gradually turning pink the next day and finally deepening to a rich red color.
This color transformation typically occurs over 24 to 36 hours.
Color change in Quisqualis indica is primarily induced by light exposure rather than factors like pollination or temperature changes. The shifting colors and the plant’s strong fragrance make it highly attractive to pollinators, especially moths and butterflies.
This adaptable plant is popular in tropical and subtropical gardens, where it can quickly cover fences or trellises with its colorful, ever-changing display.
6. Ipomea purpurea
The common morning glory, Ipomea purpurea, is known for its trumpet-shaped flowers that undergo a subtle but noticeable color change. These flowers typically open in the early morning with a vibrant purple or blue hue.
As the day progresses and the flowers are exposed to sunlight, they gradually fade to a paler shade, often appearing almost pink by the afternoon.
This color shift is believed to respond to UV light exposure and serves as a signal to pollinators. The brighter morning colors attract early pollinators, while the faded afternoon hues indicate to insects that the nectar supply has been depleted.
Morning glories are fast-growing annual vines that can quickly cover trellises or fences, providing a daily show of color transformation throughout the summer and early fall.
7. Viola tricolor
Also known as Johnny Jump Up or Heartsease, Viola tricolor is a charming little flower with multiple colors in a single bloom. The petals typically feature a mix of purple, yellow, and white. However, as the flower ages, the proportion and intensity of these colors can shift, creating a subtle but noticeable change in appearance.
Genetics and environmental factors influence the color variations in Viola tricolor. Temperature and light exposure can affect the expression of pigments in the petals.
These hardy little plants are often used as cool-season annuals in gardens. They provide colorful ground cover that seems to change its appearance as different color variations emerge throughout the blooming period.
8. Lonicera japonica
Lonicera japonica, or Japanese honeysuckle, is a fragrant vine known for its color-changing flowers. The blossoms open as white or pale yellow and gradually become creamy yellow as they age.
This color transition is often accompanied by an intensification of the flower’s sweet fragrance.
The color change in Lonicera japonica is a signal to pollinators, particularly moths and other night-flying insects. The pale, newly opened flowers are more visible in low light conditions, attracting nocturnal pollinators.
As the flowers age and change color, they become less attractive to these nighttime visitors, ensuring that pollination efforts are focused on the freshest blooms.
While beautiful, it’s important to note that this plant is considered invasive in many regions and should be planted cautiously.
9. Weigela middendorffiana
Weigela middendorffiana, a deciduous shrub native to East Asia, exhibits a fascinating color change in its flowers. The blossoms open pale yellow and gradually turn rich pink or red as they age.
This color transformation typically occurs over several days, creating a multi-hued display on the shrub.
Color change significantly affects pollinator behavior. Bumblebees, the primary pollinators of Weigela middendorffiana, preferentially visit the younger, yellow flowers, which contain more nectar.
The color change to pink or red signals the bees that these older flowers have already been pollinated and have less reward, thereby increasing the plant’s pollination efficiency.
10. Lupinus pilosus
Lupinus pilosus showcases a subtle but distinct color change as its flowers mature. The flower spikes of this Mediterranean native open from the bottom up, with the lower flowers changing color before the upper ones.
Initially, the color is a deep blue-purple, and the individual florets gradually fade to a paler blue and finally to a pinkish-white hue.
This color progression creates a beautiful ombre effect on the flower spike, with the freshest, most nectar-rich flowers at the top maintaining their deep blue color. The changing colors serve as a guide for pollinators, directing them to the most rewarding flowers.
Lupinus pilosus is not only ornamentally valuable but also plays a crucial role in its native ecosystems as a nitrogen-fixing plant, improving soil fertility.
11. Cymbidium floribundum
Cymbidium floribundum exhibits a remarkable color change that has evolved to attract specific pollinators. The flowers of this orchid species open as a pale green or yellowish color.
Over time, they transition to a deep pink or reddish hue, typically occurring over several days to a week.
Japanese honeybees can distinguish between the different color phases of Cymbidium floribundum. The bees preferentially visit the younger, pale-colored flowers offering more nectar.
This behavior ensures efficient pollination of the freshest flowers, demonstrating how flower color change can be a sophisticated adaptation to enhance plant reproductive success.
12. Tibouchina spp.
Several species in the Tibouchina genus, particularly Tibouchina granulosa, are known for their dramatic flower color changes. These tropical plants, native to South America, typically produce flowers that open in a vibrant purple or lavender color.
Over a few days, the flowers gradually fade to a pale pink or almost white shade.
Bee pollination accelerates the color change process in some Tibouchina species. When a flower is pollinated, the color changes more rapidly than in unpollinated flowers.
The quick color change signals to other pollinators that the flower has already been visited, encouraging them to focus on fresher, unpollinated blooms. This efficient system helps maximize the plant’s reproductive success.
13. Pedicularis monbeigiana
Pedicularis monbeigiana, a species of lousewort found in the Himalayan region, displays a subtle but significant color change in its flowers. The blossoms of this alpine plant open as a pale pink or white color.
They gradually deepen to a more intense pink or reddish hue as they age. This color transformation typically occurs over several days.
The color change in Pedicularis monbeigiana is thought to be an adaptation to its high-altitude habitat. The paler, newly opened flowers are more visible to pollinators in its often misty or cloudy mountain environment.
As the flowers age and change color, they signal to pollinators which blooms are freshest and most likely to offer rewards. This color-changing strategy helps ensure efficient pollination in a challenging ecological niche.
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Nancy has been a plant person from an early age. That interest blossomed into a bachelor’s in biology from Elmira College and a master’s degree in horticulture and communications from the University of Kentucky. Nancy worked in plant taxonomy at the University of Florida and the L. H. Bailey Hortorium at Cornell University, and wrote and edited gardening books at Rodale Press in Emmaus, PA. Her interests are plant identification, gardening, hiking, and reading.