Hibiscus is a pretty genus of sun-loving small trees and shrubs that have showy and tropical-looking flowers in bold shades of red, pink, white, pastel orange, and yellow. Hibiscus flowers are very easy to recognize by their large papery petals, funnel shape, and the range of hibiscus colors you can see with the sharply contrasting centers. Individual flowers usually only bloom for one or two days, but the hibiscus plant will produce blooms all summer long.
Picking the right hibiscus colors to stand out in your backyard or front yard depends largely on your climate. Tropical hibiscus plants bloom throughout the year, but they only grow in zones 9 to 12. Hardy hibiscus perennial shrubs produce very showy, large flowers and thrive in zones 5 to 11. Some tropical hibiscus cultivars grow as annuals in more temperate regions. You can also grow flowering shrubs that love the heat and do well planted in containers. You bring them inside when the temperature drops below 50°F.
Hibiscus plants are very colorful and tropical looking, and this is why they’re such a popular plant in many different climates.
One thing the hardy and tropical plants have in common is the spectacular hibiscus colors you’ll see. Some of the most attractive flowers have multi-colored petals, and there are also more rare kinds to consider with even more bold colors. To take care of any hibiscus plant or shrub, you’ll want to grow them in a well-draining soil in full sun, and you should keep the ground evenly moist.
There are hundreds of cultivars and many species available, and this makes it easy to find the perfect hibiscus color to match your needs. No matter if you want tropical or hardy cultivars, you’ll find them here. We’re going to briefly touch on four popular types of hibiscus flowers below, and then we’ll dive into why hibiscus colors change and what you can do about it.
Generally speaking, hibiscus flowers come in a broad color range, and they can be a double or single bloom. They’re usually trumpet-shaped and very showy, and they usually have brightly colored flowers with ruffled petals. These funnel-like flowers can get between 3 and 10-inches across. One feature on most hibiscus flowers is the protruding, colorful stamens that come out of the center of the flower. Flowers will last between one and three days, and the flowering shrubs or trees will produce blooms throughout the summer months.
Tropical hibiscus blooms throughout the year right into the fall months while hardy hibiscus tends to bloom from mid-summer into the fall months. Hardy hibiscus offers single blooms, and the main hibiscus colors are purple, pink, white, or red. They’re also bigger than flowers on the tropical cultivars. But, every hibiscus cultivar from small potted trees to shrubs are known for their stunning color array and their blooms.
Chinese or Tropical Hibiscus
Chinese hibiscus is also called tropical hibiscus, and it produces eight-inch wide double or single blooms in every color you can imagine but blue. The hibiscus colors include yellow, apricot, and orange. There are several varieties of hibiscus flower that fall into this category, including the Crown of Bohemia that offers golden, double-blooming flowers with orange throats, Ruby Brown that produces brown flowers tinted with orange and that have dark red throats, and Fiesta with dark orange flowers. The Chinese hibiscus has dark green, glossy leaves and it grows between 5 and 15 feet tall in zones 9 to 11. You can also grow it indoors if you put it by a sunny window.
Confederate Rose Hibiscus
Confederate roses produce hibiscus colors of red to white with bright green leaves. Blood on the Rose in one cultivar that starts as a white flower and gradually turns pink and then red within two days. Single Pink produces big, bright pink blooms, and it gets between 12 and 18 inches tall in warm climates and 6 to 8 feet tall in places that see freezing temperatures. It grows best in zones 8 to 10.
Rose-of-Sharon offers many cultivars that grow in zones 5b to 9a. It gets between 8 and 12 feet tall with greenish-gray leaves that turn bronze or gold in the fall. Bluebird produces light blue flowers while Collie Mullens has a purple-lavender hibiscus color with double blooms. Diana grows pure white blooms, Pink Giant offers large pink flowers with a burgundy splotch in the center, Red Heart has red flowers with white eyes, and Helene has white coloring with a purplish-red base.
Rose-of-Sharon is a very popular and pretty tropical plant that has a huge color range, and it’s surprisingly beginner-friendly.
Red Leaf Hibiscus
Red Leaf Hibiscus plants grow five feet tall when you plant them in zones 8 to 11. It produces pretty deep burgundy-red leaves with dark purple flowers. This plant is also commonly called false roselle or cranberry hibiscus, and other popular cultivars include Haight Ashbury that produces pink patches on the red foliage.
Rose Mallow Hibiscus
Rose Mallow is also called dinner plate hibiscus because they have 10 to 12-inch wide flowers that will only live for a single day. This hibiscus produces the biggest flowers out of all of the cultivars available, and there are several varieties of this four foot tall plant. White produces cream-colored flowers with red eyes while Etna Pink has flowers that have white petals with a pink blush, and Lord Baltimore offers flowers that are a vibrant scarlet red with yellow stamens. The leaf color will depend on the variety you choose to grow, and they thrive in zones four to nine.
Tropical hibiscus plants tend to have glossier, darker green foliage and hardy hibiscus leaves are a duller green with a heart shape to them. This is a very shrubby plant that offers dense, leafy foliage. The tropical hibiscus plant is an evergreen shrub that thrives in humid, warm climates where the temperature doesn’t dip below 50°F. Chinese hibiscus won’t drop the leaves during the mild winter months, and tropical hibiscus leaves are darker green with a very pretty glossy finish.
Hardy hibiscus is a group of flowering perennial shrubs that have deciduous foliage, and the leaves tend to be a very dull green with serrated edges. Also, they’re usually heart-shaped. Depending on the cultivar you pick out, the foliage have very deep lobes. Like most deciduous plants, Rose Mallows and Rose of Sharons all drop their leaves in the later fall months. This shrubby plant will die back to the ground, and it’s critical that you cut back the bare stems. When the weather warms again in the spring, hardy hibiscus displays a very vigorous growth habit while producing exotic flowers.
The hibiscus colors of the shrub in this genus will depend on the variety and species you choose. There are more than 200 species of hibiscus, and they come in a huge range of colors. Hibiscus colors include orange, pink, and yellow. Some of the most common options are Chinese hibiscus (H. rosa-sinensis), Confederate Roses (H. mutabilis), Red Leaf Hibiscus (H. acetosella), Rose Mallow (H. moscheutos), and Rose-of-Sharon (H. syriacus). These shrubs will add a very tropical feel to your landscape while attracting butterflies and hummingbirds.
The foliage on your hibiscus flower can usually create a pretty backdrop to make the flowers stand out more, especially if it’s dark green.
Why Hibiscus Colors Change
One of the most interesting but frustrating characteristics of this plant is the way the hibiscus colors can change. A few hibiscus plants produce the same colors at every stage during the year in every type of weather. However, most of the hibiscus color changes depend on the house of daylight they get, temperature fluctuations, and a range of other variables. We’ll explain below some of the more radical and common hibiscus color changes and reasons behind it.
For starters, hibiscus colors, like most fruit and flower colors, are made up of three main pigment groups, including carotenoids and two flavonoid types called flavonol and anthocyanins. The field of flower pigmentation can be very complex, but there are a few basic principles that emerge that we’ll go over below.
Carotenoids – The Orange, Red, and Yellow Spectrum
When you think of carotenoids, you should think of corn, pumpkins, or yellow squash. Lycopene, beta-carotene, violaxanthin, and zeaxanthin are all examples of carotenoid pigments. These are the same carotenes you take if you take vitamin supplements. This is one big reason why scientists are studying the hibiscus flowers for their health benefits for humans.
Making Vibrant Red & Bright Yellow
Carotenoids are in their most stable form in fruit and flower pigments because they get enclosed in their own small compartments called plastids. They end up between the cytoplasm of individual plant cells, and they stay out of reach for many things the plant absorbs. Pesticides won’t reach them, and most of the toxic or nutrients the plant absorbs from the air and soil don’t reach them either.
When damaging substances manage to get at the carotenoids in the pigments, they have a second line of defense in the form of antioxidant actions that also protect the plant. So, these pigments can last and last. Whatever hibiscus color you see when the flower opens, this is the color it’ll stay until it folds back up. The bright yellow and vibrant red flowers tend to hold this color, even during the hotter months.
Bold red and sunny yellow are very popular hibiscus colors, and they stand out nicely in virtually every setting.
Hot Weather Boosts the Amount of Carotenoids
The more pigment the flower produces in the bud, the brighter your hibiscus color will be, and this is true for all pigments. With carotenoids, a small amount of pigment gives you a yellow flower. As the pigment levels rise, the flowers turn vividly yellows, reds, and oranges. This is the same progression your tomato plants take as they ripen. They slowly increase their carotenoid production until it’s completely red and ripe.
Carotenoid production goes up in response to lots of sun and heat. The sunnier and hotter the weather gets, the more carotenoids your plant produces, and the brighter the reds and oranges will get. When the weather cools, carotenoid production starts to fall, and your hibiscus colors will switch to softer yellows and oranges.
This concept is exactly what the hibiscus plant does. The hotter it gets, the brighter yellow and orange your flowers will be. Saffron and Gold Mine are great examples where you can see this hibiscus color change. In sunny, hot, summertime heat, Saffron will produce stunning orange flowers and Gold Mine has bright red with contrasting yellow markings. In cloudy, cool weather, both of these hibiscus colors fade to a pale orange or golden-colored blooms. Gold Mine will lose the yellow markings completely.
The Black, Blue, Pink, Purple, and Red Spectrum
Anthocyanins are best known during the fall for the red colors in the leaves. We all know that the leaves on trees, especially maple trees, turn color in response to the weather conditions, and this is the defining trait of anthocyanin pigments. Anthocyanins are plentiful in hibiscus plants, and this gives the flowers several pretty bands of color, and it is also the reason behind the tendency to bloom with different colors, depending on a range of variables.
Blue and purple hibiscus colors are more rare, but this is because the pigment that makes them is unstable, so the colors tend to fluctuate.
Anthocyanins are Unstable
Anthocyanins are a hugely different pigment type. They are far less stable than carotenoids, and they don’t get safely enclosed in plant cells. They get created in the plant’s roots, dissolve in the water that forms the sap in the plant, and they move all of the way up the plant to the spaces where the flowers will eventually develop. The smallest environmental change or change to the plant’s health will impact the sap, and this means it also has an impact on the anthocyanins. This is why the purple and blue hibiscus colors tend to be so changeable. They come from notoriously unstable anthocyanin pigments.
One single anthocyanin pigment can be deep red or deep blue or any color in between, depending on several variables. One variable we have a decent understanding about is the pH. The levels of acidity and alkalinity in flowers change the anthocyanins’ colors in hydrangeas from pink to blue by changing the pH levels. So, with this way of thinking, you should be able to change the hibiscus color by switching up the plant’s pH levels, right? Unfortunately, pH levels in your hibiscus plant are almost 100% controlled by genetics. Inside one flower, there are pigment pockets that have different pH levels, and this creates different colors from the same anthocyanin pigment.
Anthocyanins Turn Red and Increase in Response to Cooler Weather
However, nature will do a few things to change the Ph and other anthocyanin characteristics in your hibiscus plant. You can think of this pigment as an anti-freeze chemical in your plant’s sap. In direct response to the temperature starting to drop and cool off, plants will start to create more of this pigment, and this pigment gets a much brighter red color. For some odd reason, red-hued anthocyanins have a much better anti-freeze effect on your plants. This happens to maple leaves, and it works the same way with the hibiscus.
Dry weather will also boost the reddening and darkening effect of this pigment, and it’s common to see it during mid-summer drought when the leaves develop their brilliant fall hues early. But, it does take a specific amount of light to create this pigment. So, if you mix bright sunny days with fall weather, cold nights, and less rain, you have the perfect conditions to maximize your plant’s anthocyanin production. In turn, you’ll get the brightest oranges and reds, and they also darken the pink and red hues.
High Voltage is a great example of this phenomenon. In the hottest summer temperatures, this hibiscus color is almost 100% white, and it has the barest pink blush from these pigments. As the fall weather causes cooler nights, it boosts the anthocyanins, and the light blush of pink will start to spread and deepen. In the coldest conditions, the whole flower will fill with these pigments and look pink. In mid-winter in planting zones where the hibiscus plant blooms until roughly Christmas, December can see flowers that are so red or pink that they’re hard to identify.
Anthocyanins Disappear and Degrade with Heat Exposure
Some anthocyanins have a high sensitivity to heat exposure. Enzymes located in your hibiscus plant sap will destroy these pigments in hotter weather and bright sun, and this gives you the fading effect that is so common in hibiscus flowers during scorching days. These are the hibiscus cultivars we recommend putting in a shaded spot during the hottest parts of the day.
Sleeping Beauty is a great example of this. It has anthocyanin pigments that look stunning in cloudier, cooler environments, and it produces color bands in five different colors that are very bright. However, in the summer heat, the bands recede to two or three, and in bright sunlight, they fade out very quickly. But, if you grow Sleeping Beauty inside in a window where it gets an hour or two hours of sunlight every day, it’ll give you the full range of colors that can last for two or three days. Inside in a space that is partially shaded, these pigments are protected from too much heat exposure.
Hibiscus color that depends on anthocyanin is much more prone to fading or changing colors in response to environmental conditions.
Anthocyanin Develops Best with the Right Nutrition
Anthocyanins are the pigments produced in your plant’s sap, and they’re a direct result of a reaction between protein and brix, or sugar. High brix or sugar content in the sap, coupled with the plant’s ability to produce protein, are both requirements for the plant to produce the most anthocyanin possible. Horticulturists are currently looking for ways to increase sugar content in food plants, and the easiest and most sensible way to go about this is to maximize your plant’s health. Great nutrition, soil, and care will, eventually, boost the sugar production along with the protein production, and you’ll see your hibiscus colors change in response.
Some hibiscus cultivars are extremely sensitive to any nutritional defect involving sugar, and they can stop producing blooms if the protein and sugar levels in the sap drop too low. Others may produce flowers, but the colors will be missing or pale. So, your plant’s overall health does impact the anthocyanin content.
Flavonols – The Pale Yellow and White Spectrum
Flavonols fall into the same family as anthocyanins, the flavonoid family. They also share all of the same characteristics with anthocyanins. So, they degrade with exposure to lots of bright light and heat, and they go up in a healthy plant in cooler weather. However, flavonols have their own pale yellow coloring that is very close to white. The yellow edges you see on the Sleeping Beauty cultivar come from this pigment, and it decreases and increases in response to the same things that affect anthocyanin’s pigment’s pink and blue hibiscus colors.
Arcadian spring is a great example of a type of hibiscus flower that only uses flavanols. It opens with a very soft yellow color that fades with sunlight and heat exposure to virtually pure white. In cooler conditions, the flowers will be almost fully yellow when they open, and they don’t swap to white flowers during the day.
Other Factors That Impact Hibiscus Color Changes
A few anthocyanin pigments will switch color depending on the pH levels they’re exposed to inside of the flower. The pH levels usually don’t change over time inside of the flower because the pH is determined by genetics, but it’s possible to have patches of different pH levels in the same flower that can lead to multiple colors appearing on a single bloom.
Nutrition will also factor into hibiscus color changes. Adequate levels of protein and sugar in the plant’s sap are required to produce anthocyanins. Making sure your hibiscus plant has enough nutrients and fertility is important to get more vibrant colors in any flowers that depend on anthocyanin pigments.
So, depending on which variety you pick out, the hibiscus color can change because of combinations of sunlight, temperatures, pH, or nutrition. Can you control these color changes as gardners? You can, but it’s an insect control. You do this by controlling your hibiscus plant’s environment, including fertility level, sun or shade, and protection of cold or hot weather.
Now you know a lot about hibiscus pigments. Yes, this is a very complex field of study to think about, and it’s very broad. By now, you probably know way more than you ever wanted to know. But as you watch your one blue hibiscus color turn to pink, your orange blooms to yellow, or your pink flowers deepen to red, you’ll have some idea of why and how this happens and what you can do to exert some control over it.