Quick Answers
Rose of Sharon and Althea are two common names used to refer to the same plant species – Hibiscus syriacus. They are not different plant varieties or cultivars. Rose of Sharon is the more popular and commonly used name in North America, while Althea is more often used in Britain and some other parts of Europe. So in summary, Rose of Sharon and Althea refer to the exact same flowering shrub.
What is Rose of Sharon?
Rose of Sharon is a summer-flowering shrub that belongs to the Malvaceae family, which also includes hibiscus, cotton, and okra plants. Its scientific name is Hibiscus syriacus. Some key facts about Rose of Sharon:
- Native to Asia, including China, India, and Iran
- Introduced to North America and Europe in the 1600s
- Deciduous shrub growing up to 12 ft tall and wide
- Green leaves 2-4 inches long with toothed edges
- Large, showy flowers 2-4 inches wide
- Flowers have 5 overlapping petals in white, pink, red, purple, or blue
- Blooms throughout summer, typically July to September
- Can be grown in USDA hardiness zones 5-9
- Does well in full sun or partial shade
- Tolerates heat, humidity, air pollution, and drought
- Relatively pest and disease free
- Grows in a wide variety of soil types
With its tolerance for heat and drought, Rose of Sharon is an excellent choice for gardens in warmer climates. It flowers prolifically in summer when many other plants have finished blooming. The wide color range of flowers and cultivars available also make it a versatile shrub for landscapes.
What is Althea?
Althea is simply another common name used for Hibiscus syriacus, the same species known as Rose of Sharon. It does not refer to a separate botanical variety or cultivar.
The name Althea comes from the Greek word althos, meaning “healing.” This is likely a reference to the traditional medicinal uses of Hibiscus species. The leaves and flowers were used in traditional Greek medicine, so the name Althea highlighted the plant’s healing properties.
In some references, Althea is used interchangeably with Rose of Sharon as a common name for H. syriacus. In other cases, Althea is more commonly used in Britain and other parts of Europe, while Rose of Sharon is the more popular name in North America. But they refer to the same flowering shrub species regardless.
Similarities and Differences
Botanically speaking, Althea and Rose of Sharon are identical – they are simply two common names for the same species, Hibiscus syriacus. The plant’s physical appearance, growth habit, flowering characteristics, and care requirements are the same.
Some key similarities and differences when comparing Althea and Rose of Sharon:
| Feature | Althea | Rose of Sharon |
|---|---|---|
| Scientific name | Hibiscus syriacus | Hibiscus syriacus |
| Plant family | Malvaceae | Malvaceae |
| Native range | Asia | Asia |
| Plant type | Deciduous shrub | Deciduous shrub |
| Height | 6-12 feet | 6-12 feet |
| Flower color | White, pink, red, purple, blue | White, pink, red, purple, blue |
| Bloom time | Summer | Summer |
| Sun exposure | Full sun to partial shade | Full sun to partial shade |
| Soil needs | Well-drained | Well-drained |
| Hardiness | Zones 5-9 | Zones 5-9 |
As you can see, there are no meaningful botanical differences between plants referred to as Althea or Rose of Sharon. The terms are interchangeable common names. The plants have identical morphology, growth habits, floral characteristics, and care requirements.
Etymology and Origins
Now that we’ve established Rose of Sharon and Althea refer to the same species, Hibiscus syriacus, let’s take a look at the origins and etymology behind these two common names:
Rose of Sharon
There are a few theories regarding this name:
- It is a name used in the Bible in Song of Solomon 2:1 – “I am the rose of Sharon, and the lily of the valleys.” Sharon Plain is a region in Israel, leading to the name Rose of Sharon.
- It may be a corrupted form of “Rose of Shiraz,” referring to the city Shiraz in Iran where Hibiscus syriacus may have originated.
- The name may also come from the rose-like flowers and plant’s abundance in the Sharon Plain.
The earliest known recorded use of Rose of Sharon for Hibiscus syriacus was in 1629. It has been a common name used in North America since the colonial period.
Althea
The name Althea comes from the Greek word althos, meaning “healing.” It references the traditional medicinal uses of the plant. Some theories on the name origin:
- Althea was a goddess of healing in Greek mythology, lending her name to the hibiscus known for its medicinal properties.
- It may be derived from the Greek town Althaea in Egypt where the plant was used medicinally.
- The name Alcea is similar and was used to refer to hibiscus species in older botanical texts.
Althea became a common name for Hibiscus syriacus used in Britain and other parts of Europe. But Rose of Sharon was more widely used in North America.
Cultivation and Care
Rose of Sharon and Althea are so botanically identical that they have identical cultivation and care requirements:
- Hardiness Zones: Can be grown successfully in zones 5-9 in the US.
- Sun exposure: Full sun is ideal, but partial shade is also tolerated. Needs at least 6 hours of sun per day.
- Soil needs: Prefers moist, well-draining soil. Tolerates clay, loam, sand, acidic or alkaline soil. Avoid soggy soil.
- Watering: Requires regular watering until established. Water weekly during drought or extreme heat. Good drought tolerance once established.
- Fertilizer: Apply balanced fertilizer in early spring. Some cultivars flower more profusely with fertilization.
- Pruning: Prune out dead wood in late winter. Can prune to shape and improve flowering.
- Pests and diseases: No serious pests or diseases. Aphids, scale, whitefly occasionally present. Resistant to deer.
- Propagation: Easily grown from cuttings or seed. Cultivars must be propagated from cuttings to maintain flower characteristics.
The most important care requirement is to provide full sun exposure and regular watering, especially while plants are young. But Rose of Sharon/Althea are overall quite low maintenance shrubs once established.
Landscape Uses
Thanks to their hardy nature, vibrant summer blooms, and versatility, Rose of Sharon/Althea have many fantastic landscape uses:
- Specimen planting – singly or in groups as focal point
- Hedges and screening
- Borders and foundation plantings
- Accent or feature in perennial garden
- Mixed shrub beds and cottage garden style plantings
- City landscaping and street plantings – tolerance for pollution
- Background and filler in flower beds
- Cut flowers (all parts toxic if eaten)
They provide eye-catching color in summer when many shrubs have finished blooming. The flowers attract hummingbirds and butterflies. Varied flower forms and cultivars provide diverse options for landscaping needs.
Best Companion Plants
Some great options to pair with Rose of Sharon/Althea in the garden include:
- Spirea
- Potentilla
- Russian sage
- Coneflower
- Daylily
- Rose mallow
- Black-eyed Susan
- Sedum
- Ornamental grasses
Choose companion plants with similar growth habits and overlapping bloom periods to create stunning, cohesive flower garden designs.
Popular Cultivars
Here are some of the most popular cultivars of Rose of Sharon/Althea and their characteristics:
Single-Flower Cultivars
- Aphrodite: Pure white, 6-7″ flowers
- Blue Bird: Violet-blue, 6″ blooms
- Collie Mullens: Magenta-pink, 7″ flowers
- Diana: White with red center, 5″ blooms
- Minerva: Lavender-pink, 5″ flowers
- Pink Giant: Soft pink, 7″ flowers
- Silver Dollar: White with maroon eye, 5″ blooms
Double-Flower Cultivars
- Boule de Feu: Red-purple pompom blooms
- Lucy: Rose-red very double blooms
- Magenta: Fuchsia-pink fully double flowers
- Paean Albus: White double blooms
- Red Heart: Pure white flowers, red stamens
- Rubis: Double magenta-red flowers
There are also variety of dwarf cultivars perfect for containers, smaller spaces, and tighter landscapes. Popular dwarf types include ‘Compactum’, ‘Coelestis’, and ‘Red Heart Dwarf’.
With hundreds of cultivars, there are Rose of Sharon/Althea plants suited to almost any landscape need and design taste!
Conclusion
In summary, Rose of Sharon and Althea are simply two common names used interchangeably for the same flowering shrub species, Hibiscus syriacus. While the names have different origins and interesting histories, they do refer to the exact same plant. There are no botanical differences between plants called Rose of Sharon or Althea. They have the same appearance, growth characteristics, flowering traits, and care needs. So gardeners can be confident that regardless of the common name used, they are getting the same lovely, hardy Hibiscus syriacus shrub. With its vibrant blooms and versatility, it’s no wonder this plant has garnered so many common monikers over the centuries!
