Gardening Plants & Flowers Shrubs

Rose of Sharon: Plant Care & Growing Guide

Rose of Sharon (Hibiscus syriacus) is a deciduous hibiscus species that produces abundant showy blooms in the summer and fall. The five-petal, paper-like flowers come in an array of colors (including bicolors) that reach 3" in diameter. Blooms have a prominent stamen and often a dark colored throat. This flowering shrub only requires regular watering and feeding when it's young. As it matures, it becomes a low maintenance option that is drought and heat-tolerant, easily adaptable to poor soil and urban conditions, and can live up to 20 to 30 years.

closeup of rose of sharon

The Spruce / Autumn Wood 

Rose of Sharon has a natural upright vase shape with multiple branches and medium to dark green foliage. However, it is possible to prune this shrub to a single trunk to produce a tree form. Single flower varieties produce a single blossom, while double flowers boast a double bloom that can be flat or abundantly frilly. Rose of Sharon can be planted in the spring or fall, and it has a moderate growth rate of 12" to 24" per year until it reaches its mature height of 8' to 12'. As it grows and seeds, it can become invasive in some areas.

Warning

While rose of Sharon is a stunning and easy-to-grow plant, it also spreads its seeds easily and is considered invasive in KY, PA, TN, and VA. Its spread can be curtailed by deadheading flowers before they have a chance to drop their seeds.

Common Name Rose of Sharon, shrub althea, rose mallow, Syrian mallow, Syrian hibiscus
Botanical Name Hibiscus syriacus
Family Malvaceae
Plant Type Shrub
Mature Size 8–12 ft. tall, 6–10 ft. wide
Sun Exposure Full, partial
Soil Type Moist, well-drained
Soil pH Acidic, neutral
Bloom Time Summer, fall
Flower Color Pink, purple, lavender, red, blue, white; often with dark throats
Hardiness Zones 5–8, USDA
Native Area Asia

Rose of Sharon Care

Here are the main care requirements for rose of Sharon:

  • Plant rose of Sharon in the spring or fall, 6' to 10' apart, in a location with full sun and nutrient-rich, well-draining soil
  • Tolerant of urban conditions, heat, humidity, poor soil, and drought
  • Primarily used as a specimen, hedge, or foundation plant
  • Readily self-seeds, so be prepared to remove seedlings if you don't want more rose of Sharon in your landscape.
  • Young plants will need regular watering and feeding to help them get started, but plan to water mature shrubs only during prolonged periods of drought
  • Prune regularly to keep the shrub to the desired shape.
rose of sharon plant close up
Pixabay
Hibiscus syriacus 'Lavender Chiffon' in bloom
Hibiscus syriacus 'Lavender Chiffon'  49pauly/ Getty Images
Pink/purple petals of hibiscus syriacus
Barry Winiker / Getty Images
rose of sharon bush
The Spruce / Autumn Wood

Light

Rose of Sharon prefers full sun, meaning at least 6 to 8 hours of direct sunlight on most days. But it also can grow in partial shade. However, too much shade can minimize flowering and contribute to diseases, such as fungal issues.

Soil

Rose of Sharon prefers a nutrient-rich, well-draining soil with a slightly acidic to neutral soil pH. However, it can also can tolerate slightly alkaline soil, and it can grow in multiple soil types, including loamy, sandy, and clay soils.

Water

Rose of Sharon grows best in moist soil, but mature shrubs can tolerate some drought. It won't thrive extremes: very dry or very wet conditions. So, don't let the soil fully dry out, and make sure your shrub isn't sitting in waterlogged soil.

Temperature and Humidity

Rose of Sharon shrubs are heat lovers, but they also can withstand winters with below-freezing temperatures down to -20 degrees Fahrenheit. They also can handle high humidity if they have good air circulation. Otherwise, humid conditions can promote fungal growth.

Fertilizer

Rose of Sharon can benefit from fertilizer, but it is not necessary for established shrubs unless soil quality is poor. Use a slow-release fertilizer in the late winter or early spring, following label instructions. If you want to use organic growing practices, spread and work in an inch or two of compost into the soil around the root zone in the spring.

Types of Rose of Sharon

Here are a few popular varieties of Rose of Sharon:

  • 'Blue Chiffon': This cultivar has double flowers (two layers of petals) with a purple-blue tinge that bloom from mid-summer into autumn. It grows 8' to 12' tall with a spread of 6' to 10'.
  • 'Sugar Tip': The name of this cultivar refers to its variegated leaves with creamy-white edging. It has pink double flowers and grows 6' to 8' tall and 4' to 6' wide.
  • 'White Chiffon': This variety is graced with solid white flowers; they do not have a contrasting throat. It grows 6' to 8' tall and 4' to 6' wide.
  • 'Red Heart': This shrub's flowers are ruffled and feature white petals with dark red centers. Lovers of low-maintenance landscaping will be glad to hear that this is a sterile cultivar, so it won't produce any seedlings to remove.

Pruning

This shrub grows naturally in an attractive form, so it doesn’t need much pruning. But you can tidy up its growth each year to maintain the size and shape you desire. Rose of Sharon blooms on new wood, so it should be pruned in the late winter or early spring to avoid cutting off any flower buds later in the season. Pruning back stem tips will encourage more branching and thus more flowers. Remove any damaged or diseased branches as they arise.

Additionally, some the self-seeding rose of Sharon can become messy as they spread seeds, however, you can mitigate this issue by deadheading the seed pods as they develop. This will also help address its invasive nature

Propagating Rose of Sharon

The best way to propagate this shrub is by stem cuttings. Not only is this an inexpensive way to generate a new plant, but it also allows you to continue the lineage of a variety whose flowers you especially like. The best time to take cuttings is in midsummer. Here's how:

  1. Cut a pencil-wide stem that's 4" to 6" long. Remove the leaves from the bottom half of the stem.
  2. Dip the cut end of the stem into rooting hormone.
  3. Plant the bottom third to bottom half of the stem in a small container filled with soilless potting mix. Make sure the container has drainage holes.
  4. Water to lightly moisten the growing medium.
  5. Place a clear plastic bag over the container.
  6. Put the container in a warm spot with bright indirect light.
  7. Check the growing medium every few days to make sure it remains moist. Add more water if necessary, but don't let it get soggy.
  8. Remove the plastic bag after 7 days.
  9. Check for roots in 1 to 2 months. Pull gently on the stem; if you feel resistance, the stem has rooted. New leaf growth is also a sign the stem has rooted.
  10. Wait for at least two inches of stem growth before planting it in your garden.

How to Grow Rose of Sharon From Seed

Rose of Sharon readily self-seeds in the garden, and you can sow seeds as well.

  1. Start seeds indoors roughly 12 weeks before the last projected frost date in the spring.

  2. Fill a container with soilless potting mix, and plant each seed about a half inch deep.

  3. Lightly moisten the soil by misting it, and place the container by a bright window in a room that stays between 75 and 80 degrees Fahrenheit.

  4. Keep the soil consistently moist, and you should see germination in roughly 2 to 4 weeks. 

Potting and Repotting Rose of Sharon

If you are potting or repotting a rose of Sharon, make sure to do it when temperatures are warmer, ideally in the spring or fall. Avoid going too large and choose a pot that is one to three inches larger than your plant's roots. Rose of Sharon prefers well-draining soil, so opt for a container with drainage holes and choose a high-quality potting mix. As the plant grows, you can upgrade to a larger container or prune the roots.

Overwintering

Rose of Sharon doesn't typically need any special winter care in its hardiness zones. Ideally, it should be situated in a spot that's protected from strong, chilling, drying winds. If you live in a cold part of its hardiness zones, adding a layer of mulch around its roots also can help to insulate the shrub from extreme weather.

Common Pests

The chief pest problem for this shrub is the Japanese beetle. Japanese beetles are somewhat easier to control than many other insect pests because their large size makes them noticeable. That means you'll likely spot them before they've done a lot of damage to your plant. The easiest way to kill them is to pick or shake them off the plant by hand and drop them into a container filled with soapy water. The insect breathes through its skin, so a coating of soap over its body effectively suffocates it.

How to Get Rose of Sharon to Bloom

Rose of Sharon readily blooms year after year if it has full sun and adequate nutrients and soil moisture. The showy flowers start to appear in spring and can stretch through mid-fall or even up until frost. The five prominent petals are slightly ruffled, and the tubular stamen at the center is very apparent. The blooms attract bees, butterflies, hummingbirds, and other pollinators. Deadheading (removing spent blooms) is not necessary to promote continued blooming. However, it will prevent the seed pods from forming, so it's recommended if you want to limit seedlings from sprouting.

Bloom Months

Rose of Sharon typically blooms from spring through fall. A pruning in late winter will ensure it blooms fully during the warmer months.

How Long Does Rose of Sharon Bloom?

Rose of Sharon blooms are short lived, lasting one day or, at most, three days. Full sun will encourage frequent blooming.

What Do Rose of Sharon Flowers Look and Smell Like?

Rose of Sharon blooms have a light, floral smell, and its five-petaled blooms are a tropical, hibiscus flower with papery leaves. Single flowers have a single bloom, while the double flowers have a frilly or flat second bloom.

How to Encourage More Blooms

Pruning rose of Sharon in late winter and making sure it is planted in full sun will encourage it to bloom from spring through fall.

Caring for Rose of Sharon After It Blooms

Rose of Sharon will spread its seeds quickly and efficiently, which means deadheading is necessary after it blooms, unless you want it to spread.

Deadheading Rose of Sharon Flowers

As soon as rose of Sharon is done blooming, deadhead the flowers, stopping them before the seed pod develops. This will prevent the shrub from spreading, particularly in areas where it's considered an invasive species.

Not Blooming

Several issues can result in a shrub that isn't blooming well or at all. It's possible you might have pruned too late in the spring and removed flower buds by accident. Drought also can result in a rose of Sharon that doesn't flower, so make sure to give your shrub some supplemental water during very hot and dry spells. Furthermore, soil that's deficient in phosphorus can result in low flower production and smaller blooms. Do a soil test to see whether you are dealing with any deficiencies, and apply fertilizer as needed.

Common Problems With Rose of Sharon

This shrub is generally robust in its preferred environment. However, inadequate conditions can cause some common issues to arise.

Leaves Turning Yellow

Overwatering is often the culprit when your shrub's leaves start to turn yellow. Make sure your shrub is planted in soil with sharp drainage and that it's never in waterlogged conditions. It might be necessary to move your shrub if it's located in a poorly drained spot.

Flower Buds and Leaves Dropping

Flower buds and leaves dropping from rose of Sharon is most likely caused by stress, which can be the result of too little or too much moisture.

Browning Leaves

Similar to leaves dropping, browning leaves are likely cause by stress, which could be the result of poor drainage resulting in too much moisture in the soil.

Wilted Leaves

Wilted leaves could be caused by stress due to repotting rose of Sharon. This may impact the plant for several years and pruning dead leaves can help alleviate the issue.

Stunted Growth

Rose of Sharon needs full sun, so if it's receiving too much shade that could impact both its growth rate and its blooms.

FAQ
  • Are hibiscus and rose of Sharon the same thing?

    Yes, rose of Sharon and hardy hibiscus are the same plant.

  • Does rose of Sharon spread easily?

    Rose of Sharon spreads quickly and easily, which is why it's considered an invasive plant in several states. Its spread can be mitigated by deadheading blooms before they have an opportunity to seed.

  • Is rose of Sharon low-maintenance?

    This shrub can tolerate a variety of growing conditions and doesn't need much maintenance. Pruning to keep the shrub's desired shape and to limit its spread is often the task that takes the most time.

  • Can rose of Sharon grow indoors?

    The small rose of Sharon varieties can be grown in containers indoors; however, they need good air circulation and direct sunlight to thrive. So it's best to bring your plant outdoors during the warmer months.