How to Grow and Care For Hibiscus Plants

Hibiscus flowers are some of the most stunning and certainly the largest of all perennial shrubs. With some blooms growing compactly, perfect for small garden spaces, and some clocking in at dinnerplate proportions, it’s no wonder these plants have garnered such intense popularity among gardeners. 

In addition to their beauty and prolific flowering nature, these easy-to-care-for shrubs can serve more than one purpose in the garden.

There are many different species of hibiscus. We will take a look at some of my favorites later in the article. These members of the Mallow family have origins far and wide, with many types having been naturalized in the United States. 

In general, cold-hardy hibiscus plants are native to North America and Asia. The native range of the plant depends upon the species, though, as they are not all native to and tolerant of the same climates. There are both tropical and cold hardy hibiscuses. The tropical species find their origins in the Pacific Islands and Africa.

While the two types of hibiscus have very different climates and dormancy habits, they are very much alike in appearance. Even though many species are cold-hardy, they still have a distinctively tropical aesthetic. This brings an exotic flair to gardens as far north as zones 4 and 5.

Classification

Hibiscus are perennial or evergreen shrubs and are members of the Malvacaea family, also known as Mallows. It is a large genus, encompassing more than 200 different species, spanning a wide range of origins, growth habits, and environmental needs.

They are closely related to hollyhocks and okra, interestingly. There are two types of hibiscus: tropical and cold-hardy or deciduous.

Tropical Hibiscus

Tropical Hibiscus plants are not tolerant of freezing temperatures. They are, however, commonly evergreen and capable of blooming year-round if given proper care and the right environment. There are two popular species of tropical hibiscus: H. rosa-sinensis and H. sabdariffa.

Cold Hardy Hibiscus

Hardy species of hibiscus behave as perennial shrubs. This means they lose their leaves in the fall, spend the winter months dormant, and then regrow in the spring.

Many of these plants are root-hardy only, dying back to the ground over the winter. When kept in milder climates, some varieties retain some branches.

The three most popular species of cold-hardy hibiscus are H. moscheutos, H. coccineus, and H. syriacus. Most of the hibiscus plants sold at nurseries are one of these or a hybrid of these species. 

Planting

Hibiscus plants are very easy to grow and put on a grand floral show over the summer if properly cared for. Many people prefer to purchase their hibiscus plants in the summer when they are in bloom. This is not a problem if you live in a milder climate. However, the ideal time to plant hibiscus in colder climates is spring.

By planting hibiscus in the spring, it has ample time to establish a significant root system, which is what will carry the plant through the freezing weather of the following winter. Planting or transplanting starter plants in the summer may work out just fine as well, as long as the plant has a few months to establish those roots. Planting in the fall is typically a bad idea. 

A deciduous hibiscus planted in the fall may not survive the winter as well as one planted earlier in the year with more time to adapt to its surroundings. Small plants and rooted cuttings are best planted after the threat of frost ends in the spring.

Hibiscus plants can be grown from seed. It is an uncomplicated germination process, and they grow quite quickly. Germinate hibiscus seeds in early winter, 12 weeks before the last expected frost date. Move outdoors after the risk of freezing weather has passed. 

How to Grow

As I mentioned, hibiscus plants are not difficult to grow. They tend to be flexible in terms of their environmental needs, and once established, they are very sturdy plants. When choosing a spot for your hibiscus, keep in mind that they will appreciate shelter from strong winds, as this can damage branches and flowers.

Light

Most species of hibiscuses prefer to be planted in full sun. In very hot climates, they will appreciate some shelter from the afternoon sun. In cooler climates, feel free to plant your hibiscus where it will get the greatest amount of sun possible.

Many hibiscus plants will tolerate partial shade, particularly if they get 6 hours of sun in the morning and shade in the afternoon. However, too much shade will stifle flower production and may lead to leggy growth.

Water

Both tropical and deciduous hibiscus plants like to be watered. Most of them, however, don’t like to have soggy roots. This can lead to root rot. In the weeks after planting, water your hibiscus every couple of days. Water deeply to encourage root establishment.

For the first growing season, a hibiscus must be watered at least twice weekly. Regular rainwater will compensate for this. So if the soil is moist, adding additional water is unnecessary. Overwatering can be as detrimental as underwatering. 

Once your hibiscus matures, it will be quite drought-tolerant. Hibiscuses have large root systems with multiple tap roots. They are efficient at gathering water that is available in the soil. Once mature, weekly watering is all your hibiscus should need in times of little rain. 

Soil

Hibiscus plants need slightly acidic soil rich in organic matter and nutrients. The soil’s ability to hold moisture is another important factor, as hibiscus needs moisture to thrive.

Well-draining, loamy soil is ideal. Hibiscus can also tolerate soil that is clay heavy. If your soil is clay-heavy or very dense, consider mixing in some coarse sand to improve drainage. 

To raise the acidity of your soil, add organic matter like peat moss, compost, or manure. This will help to loosen up the soil and increase the drainage around your plant’s root system. Tropical hibiscus plants thrive in soil that has a greater amount of sand in it. 

Climate and Temperature

This is where the two types of hibiscus deviate. Tropical hibiscuses are not tolerant of cold weather. If you opt to grow a tropical variety in a container, know that it should be brought indoors during the colder months. 

Indoors, tropical hibiscus will need as much light as you can provide it with and a moderately high humidity level. An indoor hibiscus will love being misted or placed in the shower to water the foliage and the roots.

Cold hardy hibiscuses are typically hardy to zone 5, with some cultivars surviving the winters in zone 4. Most of these plants have roots that survive temperatures down to -20°F. While the top of the plant will die in this weather, the roots are sturdy and tolerant. 

In terms of heat, hibiscuses are very tolerant. If you live in a warmer climate, you may need to increase watering frequency during the hottest summer months. Hibiscus can typically tolerate temperatures of 95°-115°F as long as they get adequate water. 

Fertilizer

Hibiscus plants are heavy feeders, particularly when they are in bloom. During the growing seasons, you can fertilize hibiscus every two weeks. When in bloom, increase this to once weekly. Hibiscus needs no fertilizer over the winter.

Use a fertilizer that is high in nitrogen and potassium. These are the first and last numbers in the fertilizer mix ratio. Nitrogen is responsible for the growth of foliage. This is especially important for hardy hibiscus, which dies back to the ground in the winter.

Potassium is the most important nutrient for these plants. This is what makes all of the plant’s tissues and systems strong.

Maintenance

For the first growing period, hibiscus plants will need a moderate amount of care. They must be watered conscientiously, and fertilizing will always be an important factor in hibiscus care. Once hibiscus plants are established, they can utilize water collected from the soil more efficiently. Their water needs will decrease at this time.

Hardy hibiscus must be pruned in the spring to remove dead wood and prepare the plant for new growth. This should be done as early in the season as possible after the last expected frost. Pruning before foliage grows will preserve the greatest number of buds. Pruning after buds set will result in a greatly reduced blooming season.

A delicate pruning can be done in the late summer to tidy up the plant. However, too much pruning will encourage lots of new growth that can weaken the plant for winter.

Deadheading is a great practice that will encourage your hibiscus to transfer energy and allow for more sunlight and air to circulate unopened buds. Many types of hibiscus flowers bloom for only one day. It can get tedious keeping up with daily deadheading. But don’t worry; the plant will ultimately shed its flowers.

The only disadvantage to allowing the plant to drop its own flowers is that most types of hibiscus are free seeding. This means you can end up with more plants than you bargained for in the next year. 

Pests and Diseases

Hibiscus plants are very attractive to pests and wild animals, especially their flowers. There are a handful of pests and diseases to keep an eye out for. New plants tend to be more susceptible because their foliage is tender and easier for insects to feed on. 

Aphids

Aphids are enemy number one in the gardens of many. These small insects pierce the tender growth of plants and suck the sweet sap out. An infestation of aphids can completely strip a young hibiscus plant of flowers and lead to an unfortunate blooming season.

They tend to go for the newest growth first, including flower buds, and they are visible to humans. Clusters of small green, yellow, or brown bugs covering your hibiscus buds will likely be aphids.

Another sign of aphids is a substance called honeydew. The aphids leave behind this sticky, sweet excrement and it makes a great spot for sooty mold to take up residence. 

Proper care and nutrition are the best defense against most pests. A strong plant has the greatest ability to bounce back from an infestation. To treat aphids naturally, neem oil is a good treatment. Use neem oil in the evening when pollinators are not around.

Spider Mites

More like mites and not so much like spiders, these tiny insects also feed on hibiscus as well. The leaves may begin to look shriveled, and you may be able to see tiny bits of what looks like dirt particles on the undersides of leaves.

However, spider mites are very tiny and difficult to detect in this way. The best detection is to look for the fine webbing they build on the plant’s interior.

If only a few leaves are affected, try wiping the underside of the leaves to remove mites. Insecticidal soaps and horticultural oils will help eradicate these pests. 

Whiteflies

Hibiscus is the whitefly’s favorite food. The whitefly likes to hang out underneath leaves, sucking sap and leaving that sooty mold behind. These are easy to diagnose, as a simple shake of the affected branch will send these tiny white insects flying around. They look like tiny, white moths.

Whiteflies can transmit viruses to your plants, and sooty mold weakens the plant and interferes with photosynthesis. A strong spray from the hose will help dislodge many of these insects. Then treat the plant with neem or horticultural oil to prevent their return.

Thrips

Thrips are sap-sucking insects as well. They cause flowers and foliage to shrivel and become deformed by draining them of moisture and nutrients. You may notice chlorotic spots on your hibiscus’ leaves before the foliage begins to die off altogether. 

Thrips are difficult to detect because they are so small. A good test when the plant is in bloom is to lightly shake a flower while looking into the bloom’s center. You should be able to see the thrips running around in there as they are disturbed. Neem oil and insecticidal soaps are effective treatments for thrips.

Armillaria Root Rot 

This type of fungal root rot is typically the result of overwatering. Signs of armillaria root rot are discoloration, wood cankers, and branch dieback. Additionally, a sign you might have an issue with root rot is the presence of small mushrooms growing from the base of your hibiscus.

There is no treatment for root rot. Prevention is the best solution to this issue. Once the plant has root rot, the best thing to do is remove it from the pot or ground and trim all rotting root tissue away. Then replant in clean soil and make sure the plant has good drainage. 

Botrytis

This fungal disease, also called gray mold, will manifest in unsightly discoloration of foliage and leaf drop. Prevention is best; cleaning up yard debris will go a long way toward avoiding disease. Pruning off affected branches will give your hibiscus the best chance against Botrytis. 

Hibiscus Chlorotic Ringspot Virus

This viral disease causes mottling and discoloration of hibiscus leaves. Hibiscus Chlorotic Ringspot Virus is not treatable, but not fatal either. A plant will go on about its lifecycle, with only the flowers and foliage affected by discoloration. 

Popular Varieties

With more than 200 species of hibiscus, it is impossible to list all varieties, especially since gardeners are constantly creating new and unique cultivars. However, there are a few popular varieties you should be able to find in garden stores or nurseries. Here are a few to look for.

‘Lord Baltimore’

	botanical name Hibiscus rosa-sinensis ‘Lord Baltimore’
	sun requirements Full Sun
	height 4-5 feet
	hardiness zones 4-9

This wonderful shrubby hibiscus has thin, delicate-looking leaves in bright green. The blooms are very large (10 inches around) and brilliant red. The petals have a satiny appearance and texture, adding a special luster to these stunning blooms. ‘Lord Baltimore’ is very showy and eye-catching, making a nice focal point in the garden.

‘Luna Rose’

	botanical name Hibiscus moscheutos ‘Luna Rose’
	sun requirements Full Sun
	height 2-3 feet
	hardiness zones 5-9

The Luna series of H. moscheutos are known for their compact size and large, luminous blooms. The plant will stay low to the ground, reaching only 3 feet tall. Despite the small size of this plant, the flowers are very large (7-8 inches) and have a bright raspberry color. Its blooms have a deep red eye and bright yellow pollen.

‘Midnight Marvel’

	botanical name Hibiscus moschuetos ‘Midnight Marvel’ PP24079
	sun requirements Full Sun to Part Shade
	height 4-5 feet
	hardiness zones 4-9

This stunner has amazing, deep purple foliage, the deepest of the species. This deep, dark background perfectly complements its huge (9-inch) pure red blooms. The flowers are generally so highly pigmented that they almost glow against the dark background. ‘Midnight Marvel’ has excellent cold tolerance and is hardy to zone 4.

‘Blue Chiffon’

	botanical name Hibiscus syriacus ‘Blue Chiffon’
	sun requirements Full Sun
	height up to 12 feet
	hardiness zones 5-9

The H. syriacus ‘Chiffon’ series is a personal favorite of mine. I have a lavender-blooming hibiscus variety in my own yard, but the blue variety is simply stunning. This true blue flower is semi-double petaled, with a ruffle of smaller petals inside of the five larger petals that make the foundation of the flower. This is a large cultivar with medium-sized flowers that bloom profusely in the middle of summer. 

‘Minerva’

	botanical name Hibiscus syriacus ‘Minerva’
	sun requirements Full Sun to Part Shade
	height up to 10 feet
	hardiness zones 5-9

Now this is a lovely plant. Reaching about 10 feet tall by the end of the season, ‘Minerva’ is a fast grower with a long blooming season. The foliage is deep green and glossy, and the flowers are a stunning, cool pink with a lavender hint at the edges. A deep red eye sits in the center of these medium-sized flowers, with a white stigma and pollen.

‘Grace’

	botanical name Hibiscus rosa-sinensis ‘Grace’
	sun requirements Full Sun
	height up to 4 feet
	hardiness zones 10-11

This wonderful tropical variety remains rather compact and fills in with thick, glossy green leaves. ‘Grace’ has dense foliage making it a great cultivar to grow in groupings as a hedge. It blooms prolifically, producing large (6-inch) soft pink flowers with white edges. This plant works beautifully in a tropical landscape. 

‘El Capitolo’

	botanical name Hibiscus rosa-sinensis ‘El Capitolo’
	sun requirements Full Sun
	height 4-5 feet
	hardiness zones 9-11

‘El Capitolo,’ or Lion’s Tail hibiscus, is another tropical variety with a unique personality. The blooms are double, but not in the usual sense. The base of the bloom is a large single-form bloom in red with pale yellow accents. The plant’s stigma is long and topped with a second set of ruffled petals, resembling a tail with a tuft at the end. A very unique and flamboyant flower.