Why Won’t Your Hibiscus Flower? (What’s Wrong & What to Do!)
It’s challenging enough trying to cultivate hibiscus only to enjoy its short-lived blooms for a few days max. Despite your best efforts, there may be times when it simply isn’t enough. Here is everything I’ve learned from personal experience that can prevent a hibiscus from blooming!
Hibiscus may not flowering because of 1) cool temperatures, 2) low light, 3) improper fertilizing, 4) drought, 5) excessive pruning, and 6) pests. Except for heavy pruning and pests, these problems are easy to correct and can be reversed.
Hibiscus is one of my favorite flowers to grow, along with many other gardeners. But just like everything else, it has its issues! Read forward to identify what is preventing your hibiscus plants from flowering and how to fix it.
1. Cool Temperatures
Many hibiscuses will fail to flower under 55°F and will become dormant in the winter. Warm temperatures are required for hibiscus to develop flower buds.
When your hibiscus fails to flower, the first thing you should do is check the temperature. This handy temperature monitor on Amazon will work well for this.
Remember, hibiscus are tropical plants. In other words, they don’t handle cold temperatures well.
Anything lower than 55°F (12°C) and the buds may not form at all. Even if they do grow flower buds, they’re likely to wilt and fall off before opening.
An easy fix for indoor hibiscus plants is to move them away from entryways, windows, and air vents that can be a source of cold drafts.
Once the temperature rises and the plant detects there is less risk of a potential chill, it’ll eventually form flower buds.
Due to how important it is to grow hibiscus in warm temperatures, I discuss this more in-depth in a later section, so keep reading!
2. Low Light
Insufficient lighting can hinder hibiscus and prevent flower buds from growing. To induce flower growth, hibiscus plants need at least 6 hours of full sun.
Something I struggled with before was providing enough lighting for my hibiscus. Most, if not all, species of hibiscus flourish in well-lit areas.
You can tell a hibiscus is suffering from a lack of light exposure when it has become etiolated or stretched out. The stems will be tall and thin, and the plant won’t be as bushy.
A healthy hibiscus should be lush and compact with thick and sturdy stems.
Here are some places a hibiscus is most likely to suffer from inadequate light:
- Under the shade of other plants
- In north or east-facing areas
- Indoors without supplemental lighting
Without enough sunlight, it’ll be much harder for your hibiscus plant to develop the energy and sugars it needs to form flowers.
Luckily, the solution is simple. You only need to ensure that the hibiscus plant receives at least 6 hours of direct sunlight to promote flowering.
3. Improper Fertilizing
Hibiscus plants are heavy feeders and won’t flower without enough nutrients. Over-fertilizing with nitrogen can also prevent bloom by forcing the plant to focus on foliage instead.
I’ve learned through experience that hibiscus needs to be fertilized regularly.
Now, it is possible to grow them without fertilizer. However, this lack of nutrients will undoubtedly lead to weaker growth, fewer leaves, and most importantly, fewer flower buds.
On the flip side, excessive nitrogen can cause the hibiscus to grow foliage instead of blooms. It might look healthy, yet this focus on foliage development will prevent the plant from flowering.
If you’ve been fertilizing too much, simply reduce how often you fertilize. Ideally, you should only apply a balanced liquid fertilizer, such as 10–10–10, every 1–2 months at half strength during spring and summer.
Roselle hibiscus or Hibiscus sabdariffa has been shown to benefit from additional phosphorus for growing healthier blooms.
If you don’t have one yet, try out this one from Amazon. It’s pretty effective in my experience.
Given the right solution at the right time, your hibiscus should grow plenty of beautiful flowers!
Check out the 15 Cactus with Stunning Yellow Flowers (With Photos!)
4. Drought
Underwatered hibiscus will have curled and wilted leaves and will rapidly stop blooming without sufficient water. This can be treated by keeping the soil moist and never letting it completely dry.
Although hibiscus thrives in tropical settings, they cannot handle drought well. Swamp rosemallows, or Hibiscus grandiflorus, are frequently found in marshes and wetlands.
In severe cases of underwatering, your hibiscus will wilt, and its leaves will curl in an attempt to prevent moisture loss.
Slowed or stunted growth can also be seen, causing flower buds to drop or fail to form entirely.
In cases like this, you just need to increase your watering regime. To replicate their native environments, their soil should never dry out in the spring and summer.
Such an approach might sound obvious, but this increased watering will help the plant transport the nutrients they need to grow flower buds!
5. Excessive Pruning
Excessive pruning can delay a hibiscus from blooming by removing its new growth. To help it flower, avoid pruning any new growth and let it develop flower buds.
If your hibiscus isn’t suffering from any of the previous issues, it may be helpful to look at your pruning habits.
Hibiscus are versatile plants. These plants won’t die if it loses numerous branches or stems, making them easy to shape into small trees or privacy hedges.
Keep in mind, however, that heavy pruning will reduce its chances to develop flower buds, especially if they’re being cut off.
Sadly, there is no way to undo its last pruning session. When this happens, you’ll have to wait and hope the hibiscus will grow and flower before the winter.
Remember, most hibiscus will only develop flower buds on new growth, so avoid shearing too many new stems. With a bit of luck, the hibiscus will grow new shoots and branches for plenty of colorful flowers!
6. Pests
Premature shedding of flower buds in hibiscus can be due to pests. Hibiscus bud weevils lay eggs in unopened flower buds and cause them to fall. Neem oil treatments can take too long, so it is best to remove and destroy the infested hibiscus.
Some common pests of hibiscus are spider mites, whiteflies, and aphids. In severe infestations, these pests can kill all the foliage and prevent blooming.
But if you cannot see any of these pesky critters and your hibiscus plant is heavily dropping flower buds before they open, check for hibiscus bud weevils.
Aside from heavy flower bud drops, you may also see holes in the hibiscus stems. These pests prevent blooming entirely by laying eggs in young flowers, causing them to fall off.
Hibiscus bud weevils have just recently been found in Florida in 2017. They are known to attack pink and yellow hibiscus the most and are least attracted to red.
Currently, there are no registered insecticides available for hibiscus bud weevils, but it may be possible to reduce their populations with systemic pesticides such as neem oil.
Learn How to Use Neem Oil on Plants (Plus 10 Pests That Hate It!)
Unfortunately, such treatments could take months to take effect. To protect your other hibiscus plants, it’s best to remove the infested plant and destroy all the contaminated plant parts.
How to Revive Non-Flowering Hibiscus (Promote Blooms!)
Non-flowering hibiscus plants can be revived by giving them 1) adequate fertilizer, 2) sufficient light, and 3) warm temperatures.
1. Apply Adequate Fertilizer
Hibiscus is more likely to flower when given granular fertilizer or liquid fertilizer every month in spring and summer. Avoid fertilizing in the winter.
Fertilizing hibiscus is one of the easiest and most effective ways to ensure it blooms.
You can use a liquid fertilizer monthly in the spring and summer or mix a granular fertilizer into its soil to provide a consistent amount of nutrients.
Generally, most hibiscus plants grow well when given increased phosphorus, an important nutrient for new cell growth. But instead of guessing what to use, it’s best to get a soil analysis done to see the exact needs of your hibiscus.
Regardless of what nutrients you use though, you must remember winter fertilizing is not necessary.
When the above-soil growth dies and the plant becomes dormant, this sudden intake of concentrated nutrients can burn them and severely damage your hibiscus.
2. Provide Sufficient Light
To promote flowering in hibiscus, place them in 8+ hours of full sun or 12 hours of artificial light. For direct sunlight exposure, grow them in south or west-facing locations.
Another surefire way to get your hibiscus to bloom is to supply it with enough sunlight.
My hardy hibiscus had the most flowers in 8+ hours of unfiltered sun. However, they’ll do quite well in 6 hours of direct sun or 12 hours of LED grow lights, like the one below from Amazon.
The intensity of the light is also important. If an indoor hibiscus plant is more than 4 feet (1.22 m) away from a sunny window, the light it’s receiving will be much too weak!
Even if your plants are sitting outdoors in full sun, they will suffer when there are big clouds frequently blocking out much of their needed sunlight.
A good gardener will be aware of this and try to provide their hibiscus with as much intense light as possible. Some good areas to consider are south or west-facing locations that receive the most hours of sun daily.
3. Maintain Warm Temperatures
Hibiscus grows best and produces more flowers at 65–75°F. Indoor hibiscus can be kept in warm rooms with heaters. Outdoor hibiscus can be kept warm with dark rock mulch or sun-absorbent plant covers.
Temperatures can be hard to control, especially if you’re growing outdoors. The good news? You can still keep your hibiscus warm by focusing on its soil temperatures.
One of the ways I’ve done this is by placing a 1–2 inch layer of rock mulch around the plant. The dark-colored rocks or gravel will absorb the sunlight and emit enough heat to keep the soil and plant warm.
You could also insulate the plant by keeping it under breathable plant covers to retain heat. Meanwhile, indoor hibiscus can simply be placed in a warm and sunny room.
Whatever the situation is, make sure the temperature is around 65°F (18°C) to 75°F (23°C) to trigger the plant to flower. Combined with a regular feeding schedule and sufficient light, you should quickly see your hibiscus bloom!
FAQs
Can hibiscus be grown in a pot?
Hibiscus plants can be grown inside containers. Regular 2–gallon plastic or terra cotta containers are suitable for hibiscus plants. If the pot is too small, the plant may not develop any flowers.
Will hibiscus stop flowering due to age?
Hibiscus can stop producing flowers after 15 years. However, hibiscuses are prolific plants and are known to flower even after 50 years with proper care. It is generally not common for hibiscus to suddenly stop due to their age.
Summary of Why Hibiscus Won’t Flower
When hibiscus plants fail to flower, it is often because of a lack of warm temperatures, adequate light and water, improper fertilizing, excessive pruning, and pests.
Non-flowering hibiscus can be saved by giving them adequate fertilizer in the spring and summer, 8+ hours of full sun, and warm temperatures around 65–75°F. Excessive pruning cannot be undone. Hibiscus plants infested by pests such as hibiscus bud weevils are best destroyed immediately to prevent further infestations.
Sources
- “Hibiscus” by n/a in University of Minnesota Extension
- “Hibiscus stem breakage” by W. Garrett Owen in Michigan State University Extension
- “Hibiscus flowers not flowering? Scout for the hibiscus bud weevil, UF IFAS scientists suggest” by Lourdes Mederos in University of Florida
