Hibiscus syriacus is a very ornamental summer shrub.
Hibiscus syriacus facts
Name – Hibiscus syriacus
Family – Malvaceae (mallow family)
Type – shrub
Height – 3 to 13 feet (1 to 4 m)
Exposure – full sun, part sun
Foliage – deciduous
Flowering – July to November
You’ll get magnificent flowers from this plant with proper care. Planting and pruning is easy and it resists diseases well.
Planting Hibiscus syriacus
- For indoor hibiscus read about caring for indoor hibiscus.
Hibiscus syriacus in outdoor pots
All year round, your Hibiscus syriacus shrub must be planted in a soil mix designed for flowering plants, for planting, or any universal soil mix.
- Repot in the spring, every two years at most, in a container that is a little larger than the old one.
Hibiscus syriacus in the ground
Prefer planting in fall or spring if you have purchased the shrub in a pot or a container. Usually, bare-root shrubs can be purchased in garden stores during the planting season. Plant them quickly if this is the case.
- Choose a sun-bathed area, sheltered from stronger winds.
- Follow our advice on planting shrubs.
Propagating Hibiscus syriacus
It readily propagates through cuttings in spring.
Simply keep cut stems in a vase with water, and plant as soon as a few roots appear.
- Replace water every couple days to avoid rot.
The plant also bears seeds prolifically, to the point of being invasive in some areas. It’s very common that seeds produce plants and flowers that are different from the parent plants. You’ll be growing new surprises with every batch!
Hibiscus syriacus pruning
Prune your shrub in spring.
- Remove all branches that grow inwards so that the shrub can filter light through the inside.
- After that, cut remaining stems back by about ⅔, just above an outward-facing bud.
Flowers bloom on new growth, so you won’t be losing any blooming.
- Prune your Hibiscus syriacus yearly if you want to contain its size, because it can grow quite large.
Deadheading Hibiscus syriacus
You can deadhead old blooms if you’re into details, but wilted flowers quickly fall off on their own.
All there is to know about the Hibiscus syriacus
Hibiscus syriacus, also called Althea or more poetically Rose of Sharon, is definitely one of the most beautiful flowering shrubs. Native to Southwest China and Northeast India, Hibiscus syriacus has been a favorite of enlightened gardeners and landscapers for millennia.
Greek botanists in the 1st century thought the plant came from the Syrian region, and, true to botanical practice, the name ‘syriacus’ stuck.
Summer is when it is at its best, with new flowers opening up every two or three days to replace those that die off.
This plant hybridizes very easily with pollen from many plants in the mallow family. Cross-fertilization is often successful. Seeds bear flowers that are often different from those of the mother plant. The upside of this is that there are hundreds of colors and shapes for blooms to choose from!
Its blooming is very generous, in that it is both opulent and constantly renews itself from July to October and even November if the weather stays mild.
Even if this shrub prefers warm climates, several varieties are very hardy and well suited to harsher climates.
Whatever the configuration – hedge, flower bed or stand-alone – Hibiscus syriacus will enchant you with the beauty of its flowers.
Smart tip about Hibiscus syriacus
If it freezes in your area, it is highly recommended to winterize your plant. Wrap it up with horticultural fleece towards the end of November.
Credits for images shared to Nature & Garden (all edits by Gaspard Lorthiois):
Violet Hibiscus syriacus by Manfred Richter under Pixabay license
White Hibiscus syriacus by Gernot under Pixabay license