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

How to Plant Rose of Sharon

Plant rose of Sharon after final spring frost in climates with cold winters. It can be planted in late fall in southern climates. A full sun location that receives 6 to 8 hours of bright exposure daily gives the most robust flowering. Rose of Sharon doesn’t tolerate boggy soil but adapts to even poor soil as long as it drains well. Follow these steps for planting.

  1. Dig a hole. Make the hole as deep as the root ball and twice as wide.
  2. Set the plant. Place it in the hole so the top of the root ball is even with surrounding soil.
  3. Back fill in. Use soil removed from the hole to fill in all around the root ball.
  4. Water thoroughly. Give newly planted shrubs a deep watering and provide an inch of irrigation weekly until a good root system is established.
  5. Add mulch. Spread a 2 inch layer of mulch around the base to retain moisture.
  6. Correctly space multiple plants. Allow 6 to 10 feet between full size shrubs depending on variety. Dwarf cultivars can be planted 24 inches apart.

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.

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.

Landscaping Ideas With Rose of Sharon

  • Plant dwarf varieties in containers as ‘thrillers.’
  • Create a hedge or screen with one type or different same size varieties.
  • Use as a foundation planting.
  • Add as a tall back of the border plant in flowerbeds.

Pruning

Rose of Sharon blooms on new wood, so prune in late winter or early spring. Cut back stem tips to encourage branching and flowering. Remove damaged or diseased branches as they arise.

Deadhead self-seeding rose of Sharon flowers before they set seed. This cuts down on unwanted spread and helps control this plant’s 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°F and 80°F.
  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 with full sun exposure and adequate moisture. Flowers attract bees, butterflies, hummingbirds, and other pollinators.

Bloom Months

Rose of Sharon typically blooms from spring through fall. Prune in late winter to ensure it blooms fully during warmer months.

How Long Does Rose of Sharon Bloom?

Flowers are short lived, lasting one day to three days. Full sun encourages frequent blooming.

What Do Rose of Sharon Flowers Look and Smell Like?

Flowers are a tropical, hibiscus blossom featuring five papery petals with prominent stamens. They can be single or double with many varieties displaying a contrasting throat. Fragrance is a light, floral perfume.

How to Encourage More Blooms

Prune rose of Sharon in late winter and make sure it is planted in full sun for season long flowers.

Deadheading Rose of Sharon Flowers

As soon as rose of Sharon is done blooming, deadhead the flowers before seed pods develop. This prevents the shrub from spreading, particularly in areas where it’s considered invasive.

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


    • 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.

    • 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.

    • 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.