A beautiful, blooming hibiscus plant, whether it be a multi-flowering tropical or an annual show from a hardy variety is always a sight to behold. But hibiscus not blooming can be an all too familiar gardening dilemma.
A non-flowering issue can be caused by several reasons including lack of sunlight, insufficient watering, nutrient deficiencies, and pest infestations. Thankfully, it’s a problem that can be remedied in most instances.
If you are experiencing a hibiscus not blooming issue then this is exactly the place you can learn all about the effects and issues your hibiscus might be facing, and how to correct those problems so that you will once again be able to enjoy those magnificent hibiscus blooms.
Hibiscus Not Blooming Due To Location
Tropical hibiscus can flourish in full sun. However, it is best to avoid over-exposure and extremely high heat as this can negatively impact hibiscus growth.
Hardy hibiscus thrives in partial shade. However, too much shade will stunt growing and deter flowering.
When selecting a location to plant your hibiscus, find a place in your yard where lots of morning sunlight is available, and some shade is covering the plant during the hottest part of the day.
Too Much Shade
Gardeners tend to agree that for hibiscus to grow to its full potential, the plant needs at least six hours of sunlight daily. Keep in mind that too much shade either for tropical or hardy varieties of hibiscus can impair growth rate and prevent bud set and subsequent flowers from developing.
When growing indoors, it’s fine to supplement sunlight with grow lights to secure the plant’s growth potential.
In particularly hot and dry climates, a hibiscus can take in too much direct sun. Sadly, intense sunlight can scorch the delicate petals and leaves of an otherwise healthy hibiscus plant.
In places where the summers are sweltering, you might want to consider growing your hibiscus in pots so that you can bring them indoors or under shade and where the temperature might be better controlled.
Pests Causing Hibiscus Blossom Drop
Insects can cause hibiscus flowers to drop from plants. These tiny pests can create significant problems for hibiscus blossoms. Some of these pests include:
- Spider Mites
- Mealy Bugs
Thrips are tiny insects that feed on hibiscus flower buds, resulting in the bud falling off the plant before flowering. Regular inspecting of plants along with pruning away infected areas can help to rid hibiscus of thrips.
However, be careful of shearing your plants too drastically since any new growth can attract even more trips.
Another common pest is the Mealy Bug. While easy to identify due to the unsightly white webbing that appears under leaves and around leaf nodes and stem junctions, the bug can be more challenging to remove from the hibiscus.
Once matured, the tiny Mealybugs will suck sap from your plant, resulting in withering stems and drooping leaves.
Once you spot the signature white spots, isolate the plant, if possible, so the pest will not transfer to others in the area.
Using neutral insecticides, like neem oil, can help mitigate the impact of harmful pests on your hibiscus plant.
Hibiscus Watering and Drought Stress
Tropical hibiscus plants thrive in a consistently moist environment to replicate their humid climate preferences. Whenever the top inch of soil is dry, the plant requires water.
Regular and consistent watering and avoidance of allowing the soil or plant to dry out is critical to the plant’s growth and the success of hibiscus blooms.
Drought stress affects every part of the plant, from the roots through the stems to the leaves and blooms. Smaller than average leaves and thinning foliage are key signs that a plant is stressed due to a lack of water.
If your plant is in a pot and the soil has totally dried out, you might need to submerge the entire pot into a larger tub of water to allow your plant the opportunity to rehydrate.
Over Fertilizing Hibiscus
Fertilizing a hibiscus plant with a fertilizer that contains moderate amounts of nitrogen, small amounts of phosphorous and a big helping of potassium will ensure your plant receives the correct balance of nutrients it needs to thrive.
Over-fertilizing caused by using too often or applying too much along with using feed that contains high amounts of nitrogen or phosphorous can have the opposite effect.
Choose to use either slow-release granules, powders, and spikes or a water-soluble fertilizer dependent on how many applications you wish to make per year and what condition your plants are in.
If using a slow-release option, fertilize your hibiscus four times each year. The granules and powders get absorbed by the soil gradually and offer a supply of nutrients from between 4 weeks to 3 months.
Using a water-soluble fertilizer will start working straight away and will need to be applied more often. The downside of fertilizers that need diluting with water is the risk of running off which can contaminate the local water supplies.
When using a fast-acting water-soluble method, ensure you water between fertilizing in order to flush out any build-up of salts that may otherwise lead to over-fertilizing.
Hibiscus are prone to be over-fertilized, and when this happens it can result in a lack of flowers. Consider reducing or ceasing fertilizing for a while, flush out any build-up of fertilizer with regular watering, and check soil pH to ensure roots can absorb nutrients via enriched soil.
Too Much Phosphorus
Phosphorus is one of the key nutrients in fertilizers. It is the macronutrient that helps plants convert nutrients to enhance growth and increase flowering. Phosphorus does help many flowering plants to produce blooms, but it can do the opposite when used in large quantities for hibiscus.
Too much phosphorus in the hibiscus can inhibit flower production and cause the yellowing and dropping of leaves. And, unfortunately, if left untreated, too much phosphorus can kill your hibiscus plant.
Too Much Nitrogen
When a hibiscus plant receives too much nitrogen, the chemical compound allows the plant to grow more foliage (leaves). When the plant is putting so much energy into growing leaves, it’s less likely to produce flowers on a normal schedule.
I suggest finding a fertilizer that combines an average amount of nitrogen, a low amount of phosphorus, and a high amount of potassium. Finding the right balance between these three ingredients is a critical step in helping your hibiscus grow flowers again.
Pruning Hibiscus at the Wrong Time of Year
As I mentioned above, your hibiscus will bloom once a year or year-round, depending on if it’s a hardy or tropical plant. You’ll want to keep this in mind when pruning. For both types of hibiscus, bud set will only occur on new growth.
The blossoms on your hibiscus can be impacted by pruning the plant during the wrong time of year. Prune tropical hibiscus plants in late summer or early fall. Waiting until later in the year can result in plants not developing as many branches, which can ultimately lead to fewer blooms.
Notably, pinching branch tips over the course of the flowering season will help to cultivate a bushier hibiscus with more flowers.
You should prune a hardy hibiscus plant in late winter or early spring. Bud set should begin shortly after pruning.
Your pruning may also depend on your climate. Pruning before freezing or sweltering weather is not a good idea.
If you live in an area that is cold in the earlier months of the year and hot in the later months, you’ll want to prune in periods with less extreme weather conditions.
Hibiscus in Pots Not Flowering
If your plant is growing in a pot, its location might be influencing its ability to flower. Hibiscus plants grow best when the roots of the plant are slightly crowded, so using a pot to cultivate your hibiscus is a great option.
Hibiscus may need trimming of the roots, depending on your plans for the plant. However, it isn’t necessary. You should only need to do this if you want your plant to remain the same size. If you’re repotting it into a larger container, you only need to trim away broken or damaged roots.
To trim the root, remove the plant from the pot, gently shake off the loose dirt, and then cut the bottom two inches of the root ball with a sharp knife or pairing shears. Keeping the roots in check can allow the plant to happily grow in a pot and continue to spend energy producing flowers.
Be sure to use a potting mix that allows for good drainage since the inability for water to move through the soil can saturate roots and prevent them, from absorbing water and as a result may lead to flowering issues.
Hibiscus can grow excellently in pots, just as they can in the ground. Make sure your pot is:
- Suitably sized for the plant: You can start at 10’’ and go up to larger sizes when you’re ready to grow your plant.
- Drainable: Your pot should have plenty of good-sized drainage holes and the soil must be well-draining to allow for excess water to escape.
Remember, you will need to increase the pot size if your hibiscus is starting to poke roots out of the bottom or if you want it to grow larger.
One problem with potted hibiscus might be poor drainage. If you see that leaves turn yellow or buds fall off before blooming, then poor drainage might be the primary problem for your potted hibiscus.
Roots saturated with water can lead to rot, mold, or flowering problems that can shorten the life of your hibiscus.
Once the drainage issues are corrected, and the plant is getting appropriate sunlight, the buds, blooms, and flowers will begin to develop and thrive. If you’ve overwatered your plant, try the following reversal steps:
- Add grit or perlite to soil to increase drainage
- Create space around the roots to allow the plant to get some air
- Do not water again until the soil is dry
- If your plant has root rot, cut off any dead roots
- Remove dead leaves gently
When potted hibiscus plants do grow larger than their pot or container can accommodate, they face becoming pot-bound. This is where the root system has grown too large for its container.
A pot-bound plant can cause yellowing of leaves and depleted flower production since roots will be restricted from absorbing nutrients due to the lack of space and lack of soil.
Consider what you wish to do with your hibiscus if it becomes root-bound. Do you wish to allow it to grow bigger or retain its current size?
To enable your hibiscus to grow more, you’ll need to report into a larger pot or container. If you wish it to stay the same size, you should remove it from its pot, trim the roots and then return it to the original pot.
In either case, I advise you to replace old soil with new, nutrient-rich soil.
Final Thoughts on Troubleshooting Hibiscus Flowering
Hibiscus can have problems blooming for a variety of reasons, including too much shade, overwatering, incorrect potting methods, and pests.
These issues can be easily fixed with pruning, insecticides, repotting, and checking for issues such as root rot and overgrowth of roots.
Before taking any corrective action, consider whether your plant is a hardy or tropical hibiscus. Caring for your specific variety of plants will better serve its ability to start flowering once again.