Popular for its showy trumpet-like flowers, the hibiscus tree blooms in a range of colors and sizes.
A great way to bring exotic interest to the garden, with the right care these are reliable, durable specimens. Popular with butterflies and hummingbirds, the colorful hibiscus tree is a great way to introduce life to your garden.
The plants are ideal for growing in a range of situations. While in warmer climates they thrive in garden flower beds, in cooler areas you can grow in pots either on patios or as exotic houseplants. Our guide to cultivating the hibiscus tree explains everything that you need to know from selecting the right plant for your garden to caring, pruning and propagating new plants.
These plants are popular for their exotic blooms.
Different Types of Hibiscus Tree
Native to Asia and parts of North America, there are over 200 different types of hibiscus tree. In addition to the many different cultivars there are also a range of different hybrid types. Some of the plants in this large genus are even edible.
These are typically small to medium sized plants. Most grow to a height of 5 to 6 ft. Smaller cultivars can be 2 to 4 ft in height. In optimal conditions, taller specimens can reach between 10 and 15 ft in height, depending on the cultivar. Most types achieve a spread of 2 to 8 ft. A resilient specimen you can prune the plants to a shrub like appearance. You can also allow the stems to intertwine to give a tree-like appearance.
The plants typically have dark green leaves with toothed edges. While there is some variety, most of the showy, colorful flowers produce at least 5 petals and a visible central stalk. The hibiscus flower contains both male and female parts.
Herbaceous plants, many annual and perennial types of hibiscus tree are hardy in USDA Zones 5 to 11. Flowering in the summer, plants growing in tropical climates flower throughout the year. There are around 35 different native types of hibiscus tree in the southeastern parts of the United States. The cultivar Scarlet Rose Mallow is a popular native plant that is common in Florida. This attractive, red flowering plant typically reaches a height of 4 to 8 ft.
Rose Mallows, also known as Marsh Hibiscus plants, thrive in wetlands and wet soil positions, such as close to rivers or ponds. While these plants also tolerate and even grow well in drier soils, they will require more regular watering than other plants.
The hardy hibiscus is a cold tolerant, perennial plant. It is just as attractive as the more showy tropical varieties thanks to its large flowers. One of the most common hardy types of hibiscus tree is Rose of Sharon. When in flower the Rose of Sharon is covered in white, pink, yellow or purple flowers with a distinctive, protruding central stalk.
In cooler areas of North America the hardy or shrubby Rose of Sharon (H. Syriacus) is preferable because it is better able to withstand the cold winter temperatures.
Rose of Sharon is a reliable, hardy cultivar.
The tropical hibiscus tree grows in parts of South Louisiana and Florida. More sensitive than other cultivars, one of the most popular tropical types for home gardens is H. Rosa-Sinensis. Tropical types are ideal for warm climates or cultivating as impressive houseplants.
Most varieties are perennials. They can be grown as a small shrub or a large tree. Those cultivars described as annual plants are not true annuals. They are actually tropical types that are grown as annuals in cooler climates.
Annual plants are usually grown in pots and learning how to overwinter them, as we will discuss later, means that you can keep them year after year. Amongst the most common annual types are the colorful Chinese and Red Leaf, which is popular for its deep red foliage.
There are hundreds of different tropical and hardy types of hibiscus tree. Some of the most attractive types of hibiscus tree include:
- Fringed, a unique cultivar, its long pendant flowers hang delicately from thin, arching stems,
- Scarlet Rose Mallow is another distinctive flowering type that sets flowers with seven red petals which are spaced out like a pinwheel,
- Marina produces violet-blue flowers with dark purple center and white stamen,
- Palm Springs is a tropical type. Its 6 to 8 inch flowers are orange in the center with yellow outer petals,
- Confederate Rose is a hardy rose mallow with large, showy flowers. White when they open, the blooms change color as they mature,
- Bedazzled is popular for its double, ruffled flowers which typically emerge in shades of deep orange,
- Kopper King is a hardy types with bright pink central flowers, the color fades to pink or white at the edge,
- Aphrodite is a tropical variety which produces attractive, fuschia colored flowers,
- Swamp Hibiscus is an unusual hardy type popular for large pinwheel-like flowers,
- Blue River II is a reliable, white flowering type,
- Perfect Storm is a hardy compat hybrid that flowers late in the season,
- Cajun Cocktail is a tropical cultivar with distinctive orange and yellow ruffled flowers.
Cultivars with showy, ruffled blooms are particularly attractive.
Warning, most varieties grow without overly spreading or getting out of control. However, some have a vigorous growth habit. Rose of Sharon is one such cultivar, it is classified as an invasive species in parts of eastern North America.
Where to Grow a Hibiscus Tree
These are pleasingly easy to cultivate ornamental plants. Placing them in a favorable position helps to ensure a healthy, productive specimen develops. It also helps to ensure that the plants enjoy a long, problem free life.
How Much Light Does a Hibiscus Tree Need?
These plants are best placed in a bright light.
Growers in northern climates are advised to plant in full sun. This encourages lots of healthy growth. Growers in the south, where intense dry heat is common, may find that a filtered sunlight position suits their hibiscus tree better.
If your plant seems reluctant to flower, move it to a sunnier spot. Ideally the plants should receive 5 to 6 hours of sunlight every day. In partial sun, flowering may not be as prolific.
If you are growing indoors, tropical types of hibiscus tree are best placed in a bright spot near a sunny window. Don’t be tempted to place the plant fully in the window. Keeping the plant away from direct light helps to protect the leaves from scorching.
Placing the pot on a plant caddy enables you to move the plant outside during the warm summer months and back inside during the cooler winter. Remember, when moving a plant outside, to gradually acclimatize or harden off the plant first.
The Right Type of Soil
The hibiscus tree is best placed in well draining, fertile soil. A moist, loamy soil is ideal.
Plants thrive in rich soil.
Hardy types of hibiscus tree naturally grow in wetlands. You can successfully grow these plants in damp soil areas, such as close to ponds, that are too wet for other plants.
Most types of hibiscus tree prefer an acidic soil, however they can tolerate planting in a range of soil profiles. Work in peat moss before planting to improve the acidity level of the soil. Some cultivars, such as Rose of Sharon, tolerate alkaline soil better. Like the hydrangea, the color of the flowers is affected by soil acidity.
If your soil is poor in nutrients or slow to drain, amend it with organic matter before planting.
Temperature and Humidity
Most varieties thrive in a temperature range of 60 to 90 ℉. As soon as the temperatures starts to fall toward 30 ℉ you will need to take the plant indoors or take action to protect it from the winter temperatures.
Some hardy types such as Rose of Sharon.tolerate cooler conditions and can tolerate exposure to temperatures as low as 20 ℉. However if there is a risk of frost, you will need to protect the plants or move them inside.
Tropical types of hibiscus tree struggle in cooler conditions. They are likely to die if the temperature falls below 50 ℉.
Most cultivars thrive in light, warm conditions.
The hibiscus tree does best in humid conditions. If you are growing inside a naturally humid room such as a bathroom is ideal for tropical cultivars..
How to Plant
You can grow the hibiscus tree in the garden or in a pot. Sensitive specimens, certain care and maintenance tasks such as protecting the plants from winter temperatures is made easier by growing in pots.
Planting in a Pot
Your chosen pot should be clean and have at least one drainage hole in the bottom. Stone pots encourage growth and productivity better than clay pots.
Clay pots can turn the soil alkaline over time. This is less of a problem if you are regularly repotting the plants in fresh potting soil. Unglazed clay or terracotta pots can also be used.
The hibiscus tree is a large, fast growing plant. A heavy pot is also better to hold its weight against the plant, preventing it from toppling over when in flower.
Many plants benefit from planting in pots made of natural materials.
A 10 inch pot is ideal for a young plant. Every time you repot, choose a new pot 1 to 2 inches larger than the current container.
Don’t worry about selecting a deep container, these are low or medium sized plants that tend to spread out more than they grow up. This means that the root system spreads out rather than digs down. In general, a wide pot is better than a deep one.
Planting in a pot that is too deep also encourages the plant to waste energy on root development. A more shallow container encourages the hibiscus tree to focus its energy on flowering.
To plant, place a layer of fresh potting soil in the bottom of the pot. Center the plant in the pot to check the soil level. The top of the root system should be around 1 inch below the lip of the pot.
When you are happy with the level of the soil, remove the plant from its current container and position in the hole. Continue to fill the hole, making sure that you fill all the gaps around the roots. When planted there should be a 1 inch gap between the top of the soil and the lip of the pot.
After planting do not water the plants straight away. Hibiscus tree plants can get hurt or stressed during the transplanting process. Give them 2 or 3 days to settle in their new position before watering.
Keep the freshly planted specimens in a slightly sheltered position until new growth appears. They can then be gradually exposed to direct sunlight.
Plants growing in pots benefit from repotting once every few years. The hibiscus tree is a nutrient loving plant, repotting in fresh soil gives the plants a boost, promoting growth and flowering.
Planting in the Ground
In warmer climates, hardy types in particular are suitable for growing in garden soil. Before planting, weed the soil and work in any necessary amendments.
Wait until the last frost has passed before transplanting. As you wait for the soil to warm up, take the time to harden the plants off.
When you are ready, dig a hole large enough to hold the plant. Place the plant, still in its pot, in the hole to check the size. The pot should fit comfortably inside the hole with the lip of the pot sitting in line with the soil level. When you are happy with the position of the hole, remove the plant from the pot and center in the hole. Backfill with fresh potting medium and gently firm down..
If you are planting more than one hibiscus tree, space them 2 to 3 ft apart. While this may look sparse to begin with, the plants soon fill out.
Mulch around the base of the plant. This deters weed growth and also helps the soil retain moisture during warm, dry spells.
Caring for a Hibiscus Tree
Once planted, hibiscus tree care is largely straightforward. However the requirements of the plant can vary depending on whether it is a hardy or tropical variety and its growing location.
When to Water
A growing hibiscus tree is a thirsty plant. Aim to keep the soil moist. Remember that the soil should be well draining, if it retains too much moisture the roots can develop rot.
Indoor and tropical types require regular watering from spring until early fall. Plants growing in warm or sunny conditions may require watering as frequently as once a day. This can be reduced in winter when the plants are dormant.
If you are growing in pots, ensure that the top inch of potting mix is dry before watering.
Hardy specimens that are not planted near a pond or wet area also require regular waterings. Those planted close to a water source require less frequent watering.
Collecting your own rainwater is a good way to keep plants hydrated without increasing your water usage.
If you underwater your hibiscus tree it may struggle to flower.
How to Fertilize
A regular dose of an appropriate fertilizer encourages growth and flowering.
Apply a regular dose of liquid fertilizer. This can be incorporated into your watering routine and dispersed evenly over the soil, nourishing the entire root system.
A fertilizer that is high in potassium and nitrogen is ideal because it encourages lots of colorful, healthy flowers. Both fish emulsion and a seaweed extract fertilizer are effective, organic choices. Apply a dose diluted to half its strength just before flowering begins. Continue to apply a regular, diluted dose once every 2 to 3 weeks throughout the flowering period.
Avoid applying fertilizers that are high in phosphorus. Too much phosphorus, particularly if it accumulates in the soil, can kill the plants.
A compost bark or worm castings can also be worked into the soil once a year. This helps to restore nutrients to the soil and promote healthy growth.
Pruning a Hibiscus Tree
There are largely compact plants. While there is no need to prune on a regular basis, they do seem to like the attention.
Hardy types of hibiscus tree benefit from an annual prune in the late fall or early winter. This can begin as soon as the plants are established, from year 2 onwards.
You can also use garden scissors to cut back the plants after flowering has finished for the year. At this point remove any dead, damaged or diseased branches as well as any old wood that is forming in the center of the plant. This helps to promote air circulation as well as keeping the plants looking neat and tidy.
Don’t worry about pruning your hibiscus tree too aggressively. These plants tolerate hard pruning.
You can also prune to rejuvenate older plants in early spring. Growers in colder climates often prefer to prune in early spring. Leaving a little excess growth on the plants over the fall and winter months helps to protect them from cold temperatures and winter freezes.
Pruning in the spring stimulates the budding process, encouraging the plant to flourish throughout the summer months. If you are pruning in late summer try not to time the branches back too far, this can hinder late season flowering.
How to Over Winter
Hardier specimens can tolerate winters in zones USDA 4 or 5. Any colder and you will need to protect the plants. Tropical types are only hardy in USDA Zones 10 and warmer.
During the winter months the leaves may yellow. This is common in overwintering specimens. Continue to water regularly, when the soil is dry to the touch.
Protect tropical cultivars from cold weather.
If your growing conditions are too cold, you will need to take further action to successfully overwinter your hibiscus tree. You can either bring them inside to enjoy as a houseplant or allow the plants to go dormant and store overwinter.
Plants growing in pots can easily be moved indoors as the fall starts to turn to winter. Placing the plants on a plant caddy such as a Patio Plant Trivet enables you to easily move them around your home. Bring the hibiscus tree inside before the temperature drops below 60 ℉. You may need to prune back larger specimens before moving them inside.
Once your hibiscus tree is inside, place it in a warm spot close to a sunny windowsill. It is common for the plant to enter a slight period of shock after moving. Do not worry if some of the leaves yellow and fall from the plant. As long as it is healthy and well cared for the plant should recover in a couple of weeks.
You may find it easier to overwinter a dormant specimen. These require less care and maintenance than overwintering a live plant.
You can either wait until the plant naturally enters its hibernation or you can force it into hibernation. Cool temperatures and drought are the main triggers for hibiscus tree hibernation.
To force the plant to become dormant, reduce the amount of water you apply during the fall. If you are able to, expose the plants to temperatures down to 50 ℉. As the plant becomes dormant it starts to drop leaves and flowers.
Once it becomes too cold to keep your hibiscus tree outside, move the plant to a dark location in your home or garage. As the plant becomes dormant it sheds its leaves.
Keep the dormant plant in a cool, dark room during the winter. Check once or twice a month and water sparingly with a watering can. Apply just enough water to keep the soil from completely drying out.
If you are unable to move the entire hibiscus tree inside, you can take cuttings and overwinter these, planting them out the following spring.
How to Propagate
The easiest way to propagate a new plant is from cuttings.
Use sharp garden scissors to remove a 4 to 6 inch stem from a new, soft wood branch. Soft wood is a young branch or stem that is still soft and pliable. Older stems are woody and prone to snapping when bent.
With the exception of the top pair, remove all the leaves from the cutting. Dip the cut end in rooting hormone and pot in a small pot filled with moist, well draining potting soil.
Keep the soil evenly moist. Placing the cuttings in a propagator enables you to better control the conditions around the cuttings. It can take a few months for a healthy root system to develop.
Propagating a hibiscus tree from cuttings produces a new plant that is a duplicate of the parent plant.
You can propagate new plants from healthy cuttings.
Growing from Seed
Growing a hibiscus tree from seed is more difficult and time consuming. Not only do the seeds take a long time to germinate, they also need a lot of attention as they grow.
Before sowing the seed, use a sharp knife to make a nick or series of nicks in the hard coating. Soak the seed for up to 8 hours in a small jar of fresh water. This helps to soften the shell, making it easier for the new plant to emerge.
Sow the seed in a small pot filled with a fresh, moist potting soil. Sow to a depth of a quarter of an inch. Place the pot in a propagator in a warm, sunny position. When cultivating a sensitive specimen, a Propagator with Humidity Vents enables you to better control the surrounding conditions. Hibiscus tree seeds need the temperature to be at least 75 ℉ before they germinate.
Continue to keep the pot warm and moist. Seedlings should appear in a few weeks. In cooler temperatures it can take longer for the seed to germinate.
Following germination continue to take care of the seedling, ensuring it remains warm and the soil is evenly moist. Too much or little water or exposure to cold temperatures can cause the seedlings to fail.
As the seedling grows, you will need to transplant it to a larger pot. If you are transplanting to an outside position remember to harden off the seedling before planting. Be careful when handling developing seedlings, the fragile stems are easily damaged when handling and transplanting.
How to Encourage Flowering
The hibiscus tree is an attractive, floral plant. The eye-catching flowers are surprisingly short lived, rarely lasting for more than 3 or 4 days. However, healthy plants continuously produce flowers from spring until fall, providing a long lasting, floral display.
To prevent flower drop make sure that your plant is not exposed to any temperature extremes. The temperature should be neither too warm nor too cold. Even hardy types struggle if the temperature remains over 85 ℉ for a long period.
Flower production may also be impacted if the plant is allowed to sit in dry soil or does not receive enough sun.
Deadheading spent blooms isn’t necessary but it can help to keep the plant looking neat.
Correctly caring for the plants encourages flowers to form.
Common Hibiscus Tree Pests and Problems
Planted in a favorable position and correctly cared for, the hibiscus tree is a largely problem free addition to the garden.
Red spider mites can be a problem if humidity levels are too low. Should an infestation occur, treat the leaves with a neem oil solution. Our guide to using neem oil on plants explains how to do this safely and effectively.
Aphids can also target plants. Again infestations can be treated with a neem oil solution, insecticidal soap or simply washed off the leaves with a blast from a garden hose.
Check the foliage regularly for signs of infestation.
Mite and Whitefly infestations can also be treated with an application of homemade insecticidal soap.
Yellowing foliage is often a sign that the plant has experienced a sudden change in weather conditions. It can also mean that you are not watering the plant correctly or it requires a dose of fertilizer.
A little yellowing of the foliage during the transition from spring to fall is normal. Anything else requires investigation.
Bud drop is usually caused by exposure to extremes of temperature, under or over watering, or not enough exposure to light or humidity.
A regular pruning to remove dead wood and promote air flow helps to prevent fungal issues such as powdery mildew from forming.
If planted in an open, sunny position, on particularly hot days the leaves may burn. Specimens growing in pots should be moved to a position with a little shade to protect them. You can also shade established specimens with a plant shade.
A popular plant for bringing breathtaking beauty to the garden, the hibiscus tree is an ideal choice for focal or specimen planting or using in a small, colorful group. In a favorable position these are low maintenance plants that reward a little regular attention with a pleasingly colorful floral display. Why not add a hibiscus tree to your garden?