The Hibiscus syriacus plant, is otherwise known as the Rose of Sharon. It is a vase-shaped shrub that grows large, showy flowers.
It belongs to the Hibiscus plant genus (Malvaceae family), and blossoms from midsummer until the first hard frost.
Gardeners like this shrub for its large flowers and for the fact that it grows late into the growing season.
Though a shrub, plants may often have a small tree appearance and are often casually referred to as the Rose of Sharon tree.
The flowers come in shades of pink, red, white and blue.
The leaves begin to show in late spring. Though they are light green at first, they change to medium green by summer.
Gardener's HQ Guide to Growing Hibiscus syriacus
Hibiscus syriacus is easy to grow, and not much attention is needed for maintenance. The blossoms return each summer without much fuss.
The bush prefers full sun, and makes for a great backdrop to any garden.
When growing Hibiscus syriacus, it is important to select a place in the garden that receives partial to full sunlight.
Though plants will grow in shady areas, this type of light may prevent blooms from reaching their full potential.
It grows best in an area that is moist and has well-drained soil. It can easily drown in waterlogged areas.
The shrub is not picky about soil type. It grows well in chalk, sand, loam and clay soil types. Although it grows best in acidic soils; it can also grow in alkaline locations.
During periods of little rainfall, the shrub needs to be watered once a week.
Newly planted Hibiscus syriacus shrubs should be watered three times a week.
The flowers produce their best blooms on new wood.
It is therefore recommended that pruning Rose of sharon shrub be pruned in the winter or early spring. This should encourage new growth and help maintain tidiness.
Quick Growing and Care Guide
Scientific Name: Hibiscus syriacus.
Common Name (s): Rose of Sharon.
Growing Zone (USA / UK Hardiness): North America USDA Zones 5 to 8; Europe and UK H5 – This makes it winter hardy to about -10 to -15°C (50 to -59°F).
Best Used For / Garden Location: Borders (looks great at the back). Beds. Hedging. Cottage Gardens. Tropical gardens. Coastal Gardens. Butterfly Gardens. Low maintenance gardens.
Plant Details
Life Cycle / Plant Type: Hardy Deciduous Shrub. Perennial. Upright. Bushy. Vigorous growth.
Plant Height: Five to 12 Feet (1.5 to 3.7 m).
Plant Spread: Three to Five feet to (1 to 1.5 m).
Blooms: Summer through Autumn. Long Lasting.
Flower Details: Trumpets. Showy. Usually Pink with a darker red eyed center.
Leaf Foliage: Attractive dark green. Three lobes. Oak leaf like.
Fruit: Seed.
Growing Conditions and Location
Best Light Conditions: Full Sun for best results. Partial shade.
Suitable Soil Types: Ideally slightly alkaline or neutral pH, can survive in slightly acidic soils. Rich in Humus. Organic.
Soil Moisture: Moist. Good Drainage. Will tolerate short dry periods of drought once established.
Sowing, planting, and Propagation: Self seeds, but may not stay true to cultivar.
Ideally propagate from stem cuttings.
Enjoys a sheltered position.
Care / when to prune rose of sharon: Provide medium watering to maintain soil moisture.
Prune younger plants hard towards the end of spring to encourage bushy growth. Cut back to three buds to encourage larger flowers.
Mulch the plant's base with a couple of inches (5 to 6 cm) of manure or rotten compost following pruning.
Lightly prune decayed branches towards the end of winter or at the start of spring. Shape plants at the same time.
In colder areas provide a mulch for the winter.
Protect from pests such as Japanese beetles and whitefly. Susceptible to blight (don't grow close to vegetables such as Kohlrabi and cabbage, and to Rock cress) and rust.
Growing in pots and containers: The Rose of Sharon purple pillar cultivar tends to grow in a more tree-form manner and may be ideal for containers. Prune to prevent growing too high. Looks good on a patio. Thirsty plant, so water plentifully everyday. feed with an all purpose fertilizer. Should be fine over-wintering outdoors in most areas.
Further Information
Miscellaneous: National flower of South Korea. Tolerant to high humidity and heat. grows well in polluted urban areas and is fairly tolerant to deers. Attracts birds and butterflies to the garden.
Cultivars: Collie Mullens: Oak shaped leaves, Semi-double flowers. Pink.
Eruption: Compact, Purple tinited oak shaped leaves, large pink semi double flowers.
Lavender Chiffon: Lilac flowers, double flowers are veined and about 4 inches (10 cm) in diameter.
Maike: Upright, Dark-centered pink flowers, green leaves that become yellow during the fall.
White Pillar: Very tall (Up to 16 feet; 5 m in height), dark green leaves, single and semi double white flowers.
Blue Chiffon Rose of sharon: Lacy Blue flowers. Vigorus growth, typically reaches eight to 12 feet (2.5 to 3.45 m).
Purple pillar (Gandini Santiago): narrow growing form, reaching up to 16 feet (5 m) in height, but only a two or three feet spread (60 to 90 cm). can make a good screening plant. Buds are a dark purple, but the fluffy flowers, which bloom in summer. are a pink to purple.
Family: Malvaceae.
Native: Eastern Asia.
References and Further Reading: RHS list of Hibiscus syriacus cultivars; Cornell Woody Plant Database.
Common Questions
Is Hibiscus syriacus invasive?
There is some debate over whether Hibiscus syriacus is invasive or not in a garden setting. Some people say that it is because it can grow aggressively and take up space over other plants.
While others say that it is not invasive because it does not spread rapidly, and it is easy to control any emerging seedlings.
Outside of the garden. A lot will also depend on the region in which you are growing it.
It is considered invasive in many US states, where it can rapidly outcompete native plants. It can grow prolifically in wastelands, forests, and other areas with rich soils.
It is important to be aware of the potential for Hibiscus syriacus to become invasive.
If you wish to grow this plant in areas considered invasive, then consider using sterile cultivars. These include Diana, Minerva, and Helene.
Some steps to prevent spread in the garden if necessary include:
This can be done through deadheading flowers before seed-set. This will prevent seeds from spreading out of control.
Plants can be easily trimmed.
Unwanted plants should be removed and their root systems thoroughly dug out.
The herbicide glyphosate is also effective at controlling Hibiscus syriacus plants.
Are Hibiscus and Rose of Sharon the same thing?
Hibiscus and Rose of Sharon are not the same, yet they are! Hibiscus is a genus of flowering plants in the mallow family, Malvaceae. There are many species of hibiscus, both annual and perennial. The Rose of Sharon is a species of hibiscus, specifically Hibiscus syriacus.
Rose of Sharon is also used as a common name for many other plants. These include Hibiscus rosa-sinensis, Paeonia lactiflora, and Hypericum calycinum.
I hope that you enjoyed this guide on how to grow Hibiscus syriacus. You may also enjoy the following growing guides: How to grow members of the Hyacinthus plant Genus, Hollyhock, and Ginger Lily.
