When Does a Hibiscus Bloom | How Long Do They Flower

Originally found growing in Asia, the hibiscus is a unique plant whose blooms provide vibrant color combinations that can differ for each plant. 

As flowering plants go, hibiscus is not too difficult to care for. Since the blossoms are the main attraction of this plant, though, it’s easy to get caught up in whether or not your hibiscus is flowering properly.

When does a hibiscus bloom? Understanding when they bloom will help to uncover other facts, such as how long they bloom for and what issues can be tracked to figure out why your hibiscus isn’t properly blooming. Read on as I provide the answers to these questions and more.

When Does a Hibiscus Bloom?

There are two types of hibiscus plants: hardy and tropical. Tropical hibiscus are evergreen, meaning that they do not lose their leaves in the winter. They also can’t survive cool temperatures. Hardy hibiscus, on the other hand, are deciduous and can survive sub-freezing temperatures (down to USDA zone 5, typically).

A tropical hibiscus can flower year-round if its needs are consistently met. Hardy hibiscus flowers appear for about 8 weeks in the summertime.

How Often Do Hibiscus Bloom?

When planting a hibiscus, it is important to know whether it is hardy or tropical in order to understand its blooming cycle. Tropical hibiscus produce flowers constantly, with each blossom lasting only one day. 

Hardy hibiscus, however, only bloom in the hot months of the year. 

How Long Do Hibiscus Bloom?

Tropical hibiscus flowers show up suddenly and radiantly but in most cases only last for one to three days. In most cases, flowers open in the early morning and wilt by the evening.

Hardy varieties bloom during the warm spring and summer months. While many plants start flowering as early as June, some won’t bloom until August. Individual flowers only survive a day or so but the blooming period typically lasts for about 8 weeks.

Why Won’t My Hibiscus Bloom?

There are several reasons why your hibiscus won’t bloom, including lack of light, nutrient deficiencies, incorrect pruning, too much or too little watering, or pest infestations.

Thankfully the problem is usually simple to solve. Here’s a closer look at those issues and what can be done to fix them.

Not Enough Sunlight

Hibiscus plants stem from tropical areas like China and, because of this, need a lot of direct sunlight. 

Take note of where you have placed the plant – is there enough light, does the area lack humidity, and are there any drafts close by? If so, your hibiscus is living under conditions that are opposed to its ability to bloom, and it is time to find a spot with more sunlight. Hibiscuses need a draft-free position with full sun and high humidity.

Excess Phosphorous

Interestingly, while phosphorous is known in the gardening world to boost the blooming process of a lot of flowers, this is not the case with hibiscus. Hibiscus plants are sensitive to too much phosphorus in the soil, and a build-up of it can lead to the roots of your hibiscus lacking the ability to take in other essential nutrients. 

In addition to a lack of flowers, other symptoms that could indicate your hibiscus is exposed to an excess of phosphorous include the yellowing of hibiscus leaves and leaf drop. 

If you suspect this is the reason for your plant not blooming, switch to a balanced 10-10-10 fertilizer or even lower ratios with a 6-6-6 fertilizer that has an even ratio of nitrogen, phosphorus, and potassium. 

Pruning at Inopportune Times

The best time to prune a hardy hibiscus plant is at the end of the growing season, usually in September or October. This type of hibiscus can more easily tolerate hard pruning, just make sure you cut back well in advance of any new growth emerging.

Tropical hibiscus, on the other hand, prefers infrequent pruning and any heavy-handedness will result in a significant delay in new shoots and bud sets. 

Over or Under Watering

Hibiscus plants are known for their massive intake of water – again, they hail from tropical areas where water is naturally plentiful. However, caring for a hibiscus plant is a delicate balancing act, because too much water can prevent blooming. 

If your hibiscus is potted, ensure it is planted in well-draining soil and the container has good-sized holes for drainage, to prevent the soil from soaking in too much water. It is especially important to check your plant daily in the summer months for dryness and water accordingly. 

Remember that if the pot or container holding your hibiscus is too small, it could dry out quicker. Adding a layer of mulch can also help to retain moisture in the soil.

Nutrient Deficiencies

Hibiscus plants are known for being heavy feeders. As with most plants, one of the most effective ways to feed your hibiscus is to regularly provide it with a good hibiscus fertilizer

Potassium is one of the most important nutrients for hibiscus plants, and they will not be able to bloom without an ample supply of it. 

Remember to find a well-balanced fertilizer that contains an even ratio of nitrogen, phosphorous, and potassium. 

During the summer growing season, I recommend using a liquid concentrate fertilizer that can be diluted in water, allowing for watering and feeding at the same time. Remember to water in between fertilizing to ensure that any excess nutrient salts are flushed out.

Another related tip is to check on the pH levels of your soil. Hibiscus prefer neutral to slightly acidic soil in a pH range of between 5.5 to 7.0. Too much alkalinity can lead to a non-blooming plant. 

To increase acidity, regularly mix compost into the soil and mulch the top layer of soil around your hibiscus over winter. 

Pest Infestations

It is common for houseplants, and even those in gardens, to become infiltrated with unwanted pests – and this is true for hibiscus as well. When a hibiscus plant is riddled with pests, its flower buds fall off, preventing the plant from properly blooming. 

Take time to thoroughly inspect the leaves, stems, and especially leaf junctions and nodes of your hibiscus, searching for signs of infestation. 

The most recommended method to getting rid of pests on a hibiscus plant is to use an organic insecticide like one derived from Neem oil. According to the National Pesticide Information Center, these types of insecticides will not be harmful to the other animals in your environment.

Regular Repotting

For those attempting to grow hibiscus in a pot inside the house, there are some considerations to take, such as giving it ample sunlight. In addition, it is best practice to completely clean the pot that the plant is located in to prevent the soil within from compacting and becoming nutrient deficient. 

To prevent soil issues as well as avoid your hibiscus becoming root bound, repot every 2 to 3 years.

Should I Deadhead Hibiscus?

For many plants, deadheading is necessary to both enhance aesthetics and maintain overall plant health. 

‘Deadheading’ is where the dead flower heads are cut off or pinched out at their apex, leaving the larger structure of the plant intact. 

However, it is not necessary to deadhead a hibiscus plant. Hibiscus is known as a self-cleaning plant, meaning they drop off their flower heads and grow new ones naturally. 

Do Hibiscus Plants Come Back Every Year? 

As noted above, hibiscus plants can either be tropical or perennial (hardy). Perennial means they will return every year and bloom in their summer growing season.

Of course, this is not the case with tropical hibiscus plants. These bloom consistently throughout the year.

What Is the Lifespan of a Hibiscus Plant?

Although the older varieties of tropical hibiscus found in Asian countries and places like Hawai’i used to survive for up to fifty years, the modern house or garden hibiscus plant typically lives between five and twenty years.

This limited life span can make caring for your hibiscus a more rewarding experience – knowing that each action you take to support the health of your plant will extend its life for as long as possible.

Final Thoughts On Hibiscus Flowers

When a hibiscus plant will flower comes down to the variety of hibiscus you are growing, the conditions in which it is growing, and how well it is being cared for. Hardy varieties bloom annually whereas tropical hibiscus keep producing flowers all year. 

Just how well they bloom comes down to the soil in which they are planted, making sure they receive enough sunlight and humidity, fertilizing adequately, and striking the right balance when it comes to watering. 

Getting these factors right makes for a healthier and happier hibiscus plant and one that will provide you with vibrant, show-stopping blooms.