Rose Of Sharon
Hibiscus syriacusUSDA | Grow Zone
5-9Outdoors all year in zones 5 to 9. Anywhere colder, keep it as a houseplant. Protect it below 0°F.
- Light
- Full sun, 6 hours
- Water
- Deeply once a week
- Humidity
- Moderate humidity
- Temperature
- 65-85°F (18-29°C)
- Difficulty
- Beginner
- Growth
- Moderate
- Mature size
- 6-10 ft tall, 4-8 ft wide
- Pets
- Non-toxic to pets
Hibiscus syriacus, commonly known as Rose Of Sharon, is a stunning flowering shrub that adds vibrant color to gardens. Originating from Asia, it is cherished for its showy blooms and resilience, making it a popular choice among gardeners.
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Ideal temperature
65-85°F is where it grows fastest. Below 0°F cold damage starts.
Spacing and harvest
- Mature size
- 6-10 ft tall, 4-8 ft wide
- Plant apart
- 48-96 in
- Frost
- Hardy: survives frost
Everything it needs
9 essentials at a glance
Watering
Hibiscus syriacus prefers consistently moist soil, especially during the growing season.
Water deeply once a week, allowing the top inch of soil to dry out between waterings. In hot summer months, increase frequency to twice a week. Signs of over-watering include yellowing leaves and root rot, while under-watering may cause wilting and leaf drop.
Light
This plant thrives in full sun, requiring at least 6 hours of direct sunlight daily.
Ideal placement includes south or west-facing gardens where it can soak up the sun. While it can tolerate partial shade, reduced flowering may occur in less light.
Soil
Hibiscus syriacus prefers well-draining soil with a pH range of 6.0 to 7.0.
A mix of loamy soil with organic matter, such as compost, is ideal. Ensure good drainage to prevent waterlogging, which can lead to root issues.
Humidity
This plant enjoys moderate humidity levels but is quite tolerant of drier conditions.
To increase humidity, mist the leaves or place a humidity tray nearby. Signs of humidity stress include browning leaf edges and drooping foliage.
Temperature
Hibiscus syriacus thrives in temperatures between 65-85°F (18-29°C) and is hardy in zones 5-9.
It can tolerate brief periods of cold down to 0°F (-18°C) but should be protected from extreme heat and frost during winter.
Fertilizing
Use a balanced fertilizer with an NPK ratio of 10-10-10 or 20-20-20 during the growing season.
Fertilize every 4-6 weeks from spring to early fall. Signs of nutrient deficiency include yellowing leaves, poor growth, and reduced flowering.
Pruning
Prune Hibiscus syriacus in late winter or early spring before new growth begins.
Use clean, sharp pruning shears to remove dead or damaged branches and to shape the plant. Deadheading spent flowers can encourage more blooms throughout the season.
Repotting
Repot every 2-3 years or when the plant becomes root-bound.
Choose a pot that is 1-2 inches larger in diameter. Signs it needs repotting include roots growing out of the drainage holes and stunted growth. Carefully remove the plant, refresh the soil, and place it in the new pot, ensuring proper drainage.
Propagation
Propagation can be done through semi-hardwood cuttings taken in late summer or early fall.
Use a sharp, sterile knife to cut a 4-6 inch section, remove lower leaves, and dip the cut end in rooting hormone. Plant in a pot with a mix of peat and perlite, keeping it moist until roots develop, usually within 4-6 weeks.
When it's unhappy
Yellow leaves
Why it happens
Often caused by over-watering or nutrient deficiency.
How to fix it
Ensure proper watering practices and consider fertilizing if nutrient deficiency is suspected.
Root rot
Why it happens
Occurs due to waterlogged soil and poor drainage.
How to fix it
Improve drainage and reduce watering frequency. If severe, remove affected roots and repot in fresh soil.
Wilting leaves
Why it happens
Typically a sign of under-watering or extreme heat.
How to fix it
Check soil moisture and water thoroughly if dry. Provide shade during peak heat if necessary.
Poor flowering
Why it happens
Can result from insufficient sunlight or nutrient deficiency.
How to fix it
Ensure the plant receives full sun and consider fertilizing to boost blooming.
Browning leaf edges
Why it happens
Often indicates low humidity or over-fertilization.
How to fix it
Increase humidity levels and reduce fertilizer application if browning occurs.
Care through the year
Spring
In spring, prune back any dead wood and fertilize with a balanced fertilizer to encourage new growth. Monitor for pests as new leaves emerge.
Summer
During summer, ensure consistent watering, especially in hot weather. Mulching can help retain moisture and keep roots cool.
Fall
In fall, reduce watering as the plant prepares for dormancy. Remove spent flowers and any dead foliage to prevent disease.
Winter
In winter, protect the plant from extreme cold by covering the base with mulch. Avoid excessive watering as the plant enters dormancy.
Toxicity & Safety
Hibiscus syriacus is considered non-toxic to pets and children. However, ingestion of large quantities may cause mild stomach upset. It is always best to keep plants out of reach of curious pets and children.
Good to know
Why are my Hibiscus syriacus leaves turning yellow?
Yellow leaves can indicate over-watering or a lack of nutrients. Check the soil moisture and consider fertilizing if needed.
How often should I water my Rose Of Sharon?
Water deeply once a week, increasing to twice a week during hot summer months. Allow the top inch of soil to dry out between waterings.
When is the best time to prune Hibiscus syriacus?
Prune in late winter or early spring before new growth begins to shape the plant and remove any dead or damaged branches.
What type of soil is best for Hibiscus syriacus?
A well-draining soil with a pH of 6.0 to 7.0 is ideal. A mix of loamy soil and organic matter works best for healthy growth.
How can I encourage more blooms on my Rose Of Sharon?
Ensure the plant receives full sun and consider deadheading spent flowers. Fertilizing during the growing season can also promote more blooms.
Is Hibiscus syriacus safe for pets?
Yes, Hibiscus syriacus is non-toxic to both pets and children, making it a safe choice for gardens.
What are the signs of root rot in Hibiscus syriacus?
Signs include yellowing leaves, wilting, and a foul smell from the soil. If suspected, check the roots for mushiness.
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