Rose of Sharon (Hibiscus syriacus) is a deciduous shrub form of hibiscus, known for a profusion of beautiful flowers resembling those of hollyhock, which appear over a very long period—from early summer all the way to frost. This shrub is grown for its flowers, and without them, the plant is quite ordinary. But it is a common problem for rose of Sharon to produce lots of buds, but then to refuse to flower at all.
This is no reason to panic and discard the shrub. Although its probably too late to correct the problem for the current growing season, there are easy steps to correct the situation and ensure plentiful blooms for next year season.
Rose of Sharon is beloved for its long bloom season and showy flowers, but sometimes these flowering shrubs fail to live up to their reputation. If your Rose of Sharon isn’t flowering, don’t lose hope! In most cases, the lack of blooms can be corrected with simple troubleshooting
Common Causes of No Flowers on Rose of Sharon
There are several key reasons why your Rose of Sharon may not be flowering:
-
Insufficient sunlight – Rose of Sharon needs full sun, at least 6 hours of direct sun per day, to support prolific flowering If blocked by trees, buildings or other obstructions, it won’t get enough light.
-
Improper watering – Too much or too little water leads to issues. Overwatering causes root rot, while underwatering results in drought stress. Both inhibit flowering.
-
Nutrient deficiencies – Lack of phosphorus prevents blooming. Rose of Sharon doesn’t need much fertilizer, but more phosphorus in early spring can encourage flowers.
-
Pruning problems – Blooms happen on new wood. Not pruning older branches means less new growth and fewer flowers. But pruning after buds emerge removes them.
-
Pests or diseases – Aphids powdery mildew leaf spots and other problems weaken plants and damage buds. Inspect and treat early before extensive damage.
-
Age and decline – Older plants naturally produce fewer blooms. After 8-10 years, flowering may decrease a lot. Consider replacing with younger plants.
Tips to Get Your Rose of Sharon Blooming Again
If your Rose of Sharon fails to bloom, try these troubleshooting tips:
-
Move it to a sunnier spot – Ensure a minimum of 6 hours of direct sun per day, ideally full sun. Aim for south or west-facing exposure.
-
Improve drainage – Prevent water-logged soil. Add compost to help retain moisture in sandy soils.
-
Water 1-1.5 inches weekly – If rain is lacking, water thoroughly at soil level, not overhead.
-
Apply phosphorus fertilizer – Use an organic balanced fertilizer with more phosphorus. Apply in early spring.
-
Prune annually – Remove older branches in late winter to promote new, flowering wood. Never after buds emerge.
-
Check for pests – Scout for aphids, powdery mildew and other problems. Take early action.
-
Consider replacing older plants – After 8-10 years, renewal with younger plants can improve flowering.
When to Expect Flowers on Rose of Sharon
-
Flower buds form on new wood early in spring.
-
Blooming typically starts in early-mid summer. Peak flowering is July-August.
-
Individual blooms only last a day, but plants flower for weeks or months.
-
Cooler fall temperatures slow blooming. Hard frost ends the season.
-
In warmer zones 8-9, Rose of Sharon may bloom year-round.
-
Don’t expect many blooms the first year. Mature plants have the best floral displays.
Unique Traits of Rose of Sharon
Beyond the flowers, Rose of Sharon has other notable features:
-
Fast growing, adding 1-2 feet yearly when young. Mature height is 8-12 feet.
-
Foliage is plain – simple green leaves similar to maple. Flowers are the showcase.
-
Many cultivars with white, pink, purple, red or bicolor blooms. Forms are single, double and semi-double.
-
Cold hardy, surviving down to zone 5. Technically a type of hibiscus.
-
Produces seed pods persisting into winter. Many reseed readily, even invasively.
-
Tolerates pollution, salt, drought and poor soils. An easy, low maintenance plant when sited properly.
Don’t Give Up on Flowerless Rose of Sharon!
When Rose of Sharon fails to bloom, it’s always a letdown. But in most cases, the lack of flowers can be corrected with some simple troubleshooting. Evaluate sunlight, watering, nutrients, pests, pruning and age. Choose proven solutions like moving the plant, adding phosphorus, and proper pruning. With a little TLC, your Rose of Sharon can flower abundantly again next season!
Watering Issues
When watering your rose of Sharon, always direct the water toward the soil around the plant rather than onto the plant itself. If you spray high, you will drench the flower buds, which invites rot. Of course, rain will soak the flower beds from overhead, and you have no control over that. But if your shrub is properly located in full sun the sunlight will help dry the water off the buds after a rainfall.
Phosphorus Deficit
Rose of Sharon normally does not need much feeding, but if you notice the size or profusion of blooms dwindling, it may indicate a phosphorus deficiency in the soil, which is preventing the plant from properly converting the other available soil nutrients. A general-purpose fertilizer can correct mild deficiencies, or you can scratch in an organic bone meal fertilizer into the soil around the plant. Amounts you apply should be modest, as too much phosphorus can stunt the entire plant.
Why Aren’t My Rose of Sharon Buds Blooming?
FAQ
How do I get my rose of Sharon to bloom?
Rose of Sharon can be planted in a variety of locations, but it prefers a site with the following characteristics: Full sun: The plant needs at least six hours of direct sunlight each day to produce its best flowers. It can tolerate some shade, but too much shade can result in fewer blooms and weaker growth.
Why does my rose of Sharon not flower?
… Sharon normally does not need much feeding, but if you notice the size or profusion of blooms dwindling, it may indicate a phosphorus deficiency in the soil …Feb 20, 2022
What month do roses of Sharon bloom?
Hardy in USDA zones 5-9, rose of Sharon bushes are tolerant of a wide range of conditions, including poor soil, heat, humidity, drought and air pollution. Flowers bloom from midsummer into fall and come in colors including white, red, pink, lavender, blue and bicolors, with single or double forms.
What to do if a rose plant is not flowering?
If your roses are in soil that doesn’t have enough nutrients they may not produce as many flowers as they should. This happens when the soil is stony or sandy and the roses cannot absorb enough nutrients. You can often overcome this problem by preparing the soil in advance of planting.