What is the difference between Hibiscus rosa sinensis vs. Hibiscus syriacus? H. rosa sinensis is tropical, while H. syriacus is hardy.

It’s hard to imagine all the effort and labor that has gone into the scientific taxonomy of naming and identifying plants! But it can be helpful and even crucial, given how common names vary by region and country.

While it’s easy to assume that most plants that fall under the same name, like Hibiscus, will grow similarly in similar conditions, this isn’t always the case. Hibiscus plants come in a wide variety of shapes, sizes, and colors, and with these differences come various needs.

Let’s dive into the primary differences in these plants, so you can choose which best suits your situation, and how to best care for them.

Comparing Hibiscus Rosa Sinensis Vs. Hibiscus Syriacus

Evergreen or Deciduous?

Hibiscus Rosa Sinensis – Evergreen

Hibiscus rosa sinensis is a tropical flowering plant cultivated in tropical Japan, China, and the nearby Pacific Islands. Two white-flowered species, Hibiscus arnottianus and Hibiscus waimeae, are believed to be native to Hawaii.^[1]https://www.ctahr.hawaii.edu/hawnprop/plants/hib-arno.htm^[2]https://www.ctahr.hawaii.edu/hawnprop/plants/hib-waim.htm

It doesn’t drop its leaves when grown in warmer environments (primarily those that are consistently above 50 degrees Fahrenheit / 10 degrees Celsius.  This hibiscus can also be grown indoors in winter in colder climates.

Hibiscus rosa sinensis only grows in warmer climates where it keeps its leaves year round.

Hibiscus rosa sinensis is an evergreen perennial.

Hibiscus Syriacus – Deciduous

Conversely, Hibiscus syriacus is a deciduous perennial that loses leaves every fall and regrows them in the spring. Many of this variety of hibiscus does not thrive indoors, so for that, consider choosing one of the H. rosa sinensis varieties, such as this lovely Fiesta Hibiscus, AKA Sunset Hibiscus.

Hibiscus syriacus is a deciduous perennial and does not grow well indoors.

Hibiscus Rosa Sinensis Vs. Hibiscus Syriacus Foliage Leaves Comparison

Hibiscus Rosa Sinensis Leaves

H. rosa sinensis has leaves that are glossy, ovate, and a deep shade of green. The base of the leaf is generally smooth, while the rest of the leaf has jagged but neat serrations. There are a few minute hairs that run along the veins on the underside of the leaves. These leaves grow alternately on the stem, and are about one to three inches wide, and one and a half to six inches long.

Hibiscus Syriacus Leaves

Hibiscus syriacus leaves are glossy, obovate, palmately veined, and three-lobed. Generally speaking, they are a darker shade of green than Hibiscus rosa sinensis. The leaves grow in pairs along the stem with alternate branching. Leaves are one to two inches wide and two to three inches long with more prominent serrations on H. syriacus.

Given the many species and flowers, the leaves are the best way to identify hibiscus varieties.

What Do The Flowers Look Like?

Hibiscus Rosa Sinensis Flowers

Most flowers are bright red and five-petaled. New cultivars are available though in various shades of red, orange, pink, peach, yellow, purple, and blue. Some have double flowers, and some are bi or tricolored, like our favorite Fiesta Hibiscus, aka Sunset Hibiscus.

Because of the range of the flowers, it is best to use leaves to identify the hibiscus species. Hibiscus rosa sinensis flower throughout most of the summer, but each individual bloom only lasts a day or so.

Hibiscus Syriacus Flowers

These flowers are trumpet shaped, and come in a vast array of colors. You can find them in all shades of pink, purple, red, mauve, white, pink, blue, or bicolor. The flower throat is often a darker and sometimes contrasting color.

Comparing the Size of Hibiscus Syriacus Vs. Hibiscus Rosa Sinensis

Hibiscus Rosa Sinensis Size

There are many cultivar variations of H. rosa sinensis, with new hybrids and cultivars being produced all the time. Still, most of these plants grow to be eight to sixteen feet tall and five to ten feet wide. This only happens, though, if it is grown outdoors in its appropriate USDA hardiness zone. Plants that are kept in containers or indoors for part of the year will likely not reach that size.

Hibiscus Syriacus Size

Like rosa sinensis, new cultivars and hybrids are created every year, and there can be considerable variations between the cultivars. The majority of them grow to be eight to twelve feet tall and about six to ten feet wide. However, they do not grow to be this size if they are confined to a container or spend part of their year indoors.

In What USDA Hardiness Zones Do These Hibiscus Grow Best?

Hibiscus Rosa Sinensis Hardiness Zones 8-11

Hibiscus rosa sinensis is best suited for USDA hardiness zones eight through eleven. They are tropical, not hardy.

Hibiscus Syriacus Hardiness Zones 5-9

Hibiscus syriacus grows best in zones five through nine. They are considered hardy, not tropical. They can grow outside of these zones if they are kept indoors on cool nights and the cold months, and outdoors during warm days and warm months.

Can They Be Grown Indoors?

Both the rosa sinensis and syriacus hibiscus can be grown indoors. However, it is important to note that both prefer outdoor conditions and should be moved outside whenever the weather permits. This allows them to get maximum sunshine, and encourages blooms.

Check out our favorite Hibiscus rosa-sinensis, the vividly colored sunset or fiesta hibiscus as well as some of the intriguing benefits and uses of these wonderful flowering plants.

You may also enjoy this article on Rose of Sharon names, which is a common name for hibiscus.