The Hibiscus tree belongs to the flowering plants’ genus and Malvaceae family including more than 200 varieties of which some are edible, and some are not. It is native to the tropical and warm temperate regions and is being cultivated as an ornamental plant due to its beautiful flowers. Hibiscus leaves are smooth and lobed and are covered in plant hairs known as trichomes. The flowers can be born both in the form of flowering clusters and singly. A whorl of leaf-type bracts surrounding the sepals is common in the hibiscus tree. Typically, its stamens are fused into a specific tube. Hibiscus and other members of this genus have characteristically capsule fruits and spiny pollens. This tree does not require much care and management for growth, development, and flowering. Growers can get good growth by the optimal care and provision of the right climatic conditions.
How do grow the Hibiscus Tree?
Hibiscus tree grows well in the USDA hardiness zone of 9-11 and some hibiscus varieties can tolerate little fluctuation in the prevailing climatic conditions. Hardy species can grow well in the 3-8 zones as well but these species shed their leaves in the fall season. The leaves appear back in the spring but the leaves and flowers can stay all year round in properly managed indoor growing conditions.
Hardy Species of Hibiscus Tree
Hardy species of this tree can be grown as perennial plants in all regions of the United States. Hardy plants go dormant in the cold and winter seasons and their normal growth is resumed in the spring. Growing hibiscus trees as perennial plants in the gardens and growing spaces help to boost the microbial biodiversity in the soil, attract pollinators, and prevent erosion. Thereby it significantly improves the physical, chemical, and biological properties of the soil than in turn supports better plant growth and production. All these hardy plant species thrive well in partial shade and full sun conditions and can easily adapt to the wide range of stressful conditions and growing mediums.
It is also known as the rose of Sharon and is a remarkable tree with lush growing habits. It is native to some Asian regions and is well known for its varied and palleted blossoms with ruched, and double-layer petals. Scarlet and swap rose mallows can adapt to a wide range of soils including wetlands, dry, and nutrient-depleted soils. It can easily tolerate soil and air pollution, so it is an ideal choice for urban gardens and polluted sites. Modern cultivars have broad variations in the scale ranging from dwarf varieties (6-10 feet) to tall varieties (8-12 feet). Dwarf varieties are ideal choices for container gardening and indoor growing in space-limited conditions.
This plant is native to the Eastern swampy regions of the United States and can grow 3-4 feet wide, and 6-10 feet in length. It is well known for its crimson unique blossoms and is easily recognizable due to its pointed petals. It’s compound and palmate leaves echos the specific star-shaped appearance of the flowers with finely toothed and skinny edges.
This species can grow 3-4 feet wide and 6-10 feet tall. Its striking flowers can reach the size of diner plates. Its flowers have pink, red, and white colors and sometimes these flowers have bicolor blends. Its leaves are velvety and broad and have toothed edges. It is native to the wetlands and survives well in the full sunny conditions and the moist soil. Growers can also observe good growth in the less favorable conditions as well by providing the right care and management.
Tropical Hibiscus Species
Hibiscus rosa sinensis
This specie produces glossy leaves with juicy blossoms bursting in the starburst shades. Chinese or tropical hibiscus is an amazing choice for the growers seeking colorful and showy statements. This plant can be easily grown indoors as a houseplant, but a provision of bright light, fertilizers, and water are greatly important to get good growth and development.
It is also known as red leaf hibiscus and is a popular ornamental plant due to its floral design and attractive foliage. It is known to be native to the East African regions and is well known for its palmate and wine-colored leaves that resemble Japanese maples. This plant produces pink flowers during the summer season in tropical areas. It rarely blooms in the annual growing habits, but its foliage also serves good ornamental functions. It produces stunning flowers in the fall and summer that turn bronze-colored in the autumn season. Its leaves have a tangy flavor and are edible and younger leaves also retain the color after cooking. Typically, this tree can grow 24-30 inches in width and 3-5 feet in length.
This hibiscus plant is not much common in the United States but is gaining significant popularity over time. Roselle is being grown more for its calyx and less for the flowers. Its sepals are succulent and provide an envelope to the fertilized edible seeds. These are rich in vitamin C and have a delightful zingy flavor. It can grow to a length of 3-5 feet in the gardens and produces burgundy veins and stems with cream-colored flowers and emerald foliage. This plant is also available in the farmer’s market in the late fall and summer. Creative farmers sell decorated calyx studded stems with textural elements. Its tea is also used as a traditional household staple, and traditional beverage.
Hibiscus trees can tolerate a great range of soils and can be easily grown in both wet and dry conditions. Better hibiscus growth can be observed in the well-draining and moist soils. The addition of organic matter, compost, peat, and muck soil is greatly helpful to improve the physical, chemical, and biological properties of the soil. Different types of growing media are also available in the market and gardening stores and growers can purchase any according to the requirements. Making compost at home and adding organic matter to the soil is a cheaper alternative as this plant does not die in the absence of exactly the right type of soil.
Hibiscus tree grows best in the slightly acidic soils between the pH range of 6.5-6.8. Growers can easily change the soil pH to this range by the addition of different amendments and grow mixes. Determination of soil pH is a prior requirement before adding any amendment. Soil pH meters are available in the market and growers can check pH at home. Moreover, they can also consult the local agricultural services providers, soil testing laboratories, and agriculture extension workers for soil pH testing.
Hibiscus trees grow best in full sunny and partial shade conditions. A minimum of about 2 hours of sunlight exposure is a must for blooming stimulation. Insufficient exposure to the light causes bushy growth and less to no blooming. Its exposure to sunlight should be reduced in the presence of higher temperatures. The watering needs of the growing hibiscus plants goes up in the presence of high temperature and more sunlight. Therefore optimization of these three factors is a must approach to get good growth and development.
More exposure of plants to direct and scorching sunlight can cause sunburn and chlorophyll destruction in the leaves. Although this plant can easily adapt to a wide range of growing conditions, more variation can cause white sunburn effects. This plant produces more buds in the summer heat provided by the better watering scheduling.
Hibiscus plants can grow in depleted soils but respond well to the addition of organic and inorganic fertilizers. Consistent and planned fertilizer application according to the soil nutrient status and growing needs helps to produce better growth, development, buds’ formation, and flowering. The use of inorganic fertilizers is not a good approach as these synthetic chemicals pose threats to beneficial insects, soil biota, and the environment.
The problem of weeds and soil drying around the hibiscus trees can be reduced by mulching. Mulching also protects the roots of growing plants from the rain splashes and harsh elements. Organic mulching is much more effective than inorganic mulching as the decomposition of organic materials constantly releases nutrients to the soil. Moreover, mulching is also helpful for temperature regulation and conserving soil moisture contents. Mulching to the depth of about 2-3 inches is recommended for supporting the hibiscus growth and development.
Regular watering is required for better growth and flowering of the hibiscus tree. Watering is a simple but challenging task as it requires the right and oriented adjustment according to the prevailing situation and microclimate. Hibiscus is a water-loving tree, but growers should be careful about the quality of water. The presence of contaminants and pollutants can cause adverse effects on the roots and foliage of growing plants. Water the plants when the upper few inches of the soil are getting dried and don’t allow the water to stand in the soil. The watering requirements of the plants are variable according to prevailing conditions so the watering schedule should be decided according to plant needs during a specific time of the year. Overwatering can cause root rotting, and dried soils cause insect pest attacks. Therefore, adjustment of the watering schedule helps reduce the disease occurrence and insect pest attack.
The Hibiscus plant cannot tolerate the colder temperature and requires a warm temperature for bud formation and flowering. Growers must maintain optimal temperature conditions in both indoor and outdoor conditions. Colder temperature causes dropping off of the buds and reduced flowering. Even though this plant can adapt to a wide range of prevailing conditions it cannot withstand sudden extreme changes in humidity and temperature. Never place the plants near the entryways, TVs, radiators, and drafty areas.
Hibiscus tree grows well in humid conditions and growers should maintain good humidity in both outdoor and indoor growing conditions. Misting and water spraying is a good approach to improve humidity in outdoor conditions while the use of humidifiers is the best approach for indoor growing. Alternatively, growers can also place gravel-filled trays below the hibiscus pots. Watering these gravel-filled trays also helps to improve the humidity level in the surroundings.
Regular pruning is required to maintain the shape, remove the dead parts, and encourage good quality blooms. Hibiscus trees can tolerate heavy pruning so growers must prune all larger and smaller plants. Removal of flowering buds along with the foliage causes the plant to bloom after a long time. Selective trimming of the leggy growth is recommended for protecting the rest of the plant. Pruning plant in the late winter is a good approach to encourage bushy growth.
How to grow the Hibiscus Tree from seeds?
Hardy hibiscus varieties are easy to grow from the seeds and vigorous germination can be assured by following the right care and management. While Chinese hibiscus has slowed growing habits and growers should start it with seedlings and nursery plants. All hibiscus plants can be easily started from stem cuttings but the new growth from healthy seeds assures good and vigorously growing seedlings. The outer layer on the hibiscus seeds can slow down the germination process and the problem can be reduced by soaking the seeds overnight. Nicking the seeds with the knife and sandpaper also helps to speed up the germination process. Better germination requires optimal temperature in the soil and surroundings so the use of heat maps is a good idea for the colder regions.
How to grow the Hibiscus Tree by Propagation?
Propagation by Cutting
The Hibiscus plant can be easily propagated by using stem cuttings. The selection of good quality and disease-free plants is the best approach to ensure better growth and development. Propagating this plant by using stem cutting is an ideal choice for tropical and hardy hibiscus species.
- Mid-summer is the best propagation time for the hibiscus plant.
- Select the branches with a green and smoother growing pattern.
- Look for the disease-free stems having dark green, smooth, and plenty of leaves.
- Taking cuttings from the darker green, and slighter brown stems is also fine.
- Avoid propagation in the winter and autumn as propagation in this time takes a significantly longer time.
- Avoid taking hibiscus cuttings during the late summer conditions as it can cause compromised growth and development.
- The rooting of the woodier stems is harder and taking cuttings in the late summer causes cuttings to become woodier.
- Use a sharp knife or scissors to take the cutting and avoid placing the cuttings on the contaminated floor.
- Avoid taking numerous cuttings from single-parent plants as it can affect the growth pattern of the parent plants.
- Taking 5-6 cuttings is enough for one-time propagation.
- Wipe the pruning scissors and shears with a damp, clean cloth to prevent rusting and bacterial attack.
- Remove all leaves on the cutting and allow only 2-4 leaves to stay.
- If the remaining leaves have a large size then cut them in the horizontal pattern to avoid wilting.
- Never pull the leaves from the cuttings as it can damage the stem fibers.
- Cut the bottom of the stem diagonally to encourage better growth.
- Cutting through the eye is even more helpful to support good growth. Eyes are the points where leaves emerge from the stems and these points have natural hormones to boost the growth.
- Take the cuttings from the softwoods or new growth.
- Cutting should have 4-6 inches of length to support better rooting and growth.
- Trim the bottom of the cutting just below the node where the leaf was growing.
- Dip the cutting in the good quality rooting hormone to encourage good rooting.
- Place the cutting in good quality and well-drained soil.
- Prepare to grow media by adding perlite and potting soil in the 50-50 ratio.
- Use of organic materials, and compost and thoroughly water the rooting soil.
- Stick the soil around the cutting to support good rooting.
- Place the plastic cover over this cutting but don’t allow the touch between a plastic bag and cutting leaves.
- Slightly open the plastic bag or make some holes in this bag to allow proper airflow and ventilation.
- Ensure wetness of the soil or grow media until the cuttings are properly rooted.
- Usually, the cuttings are rooted within eight weeks. And can be placed in the bigger pots after this time.
- The success rate of propagating the tropical hibiscus is less than the hardy hibiscus. So, use multiple cuttings for efficient propagation.
Air layering is an efficient way to propagate the hibiscus tree. In this process, the existing stem is used for growing the new plant.
- Cut the bark of the disease-free stem into two different points at a distance of about 1 cm.
- Remove the outer bark and expose the white wooden layer.
- Apply rooting hormone on the exposed wooden parts.
- Moisten the sphagnum moss and pack it around the cut area.
- Use clear, and contaminant-free plastic for this purpose.
- Seal this plastic specifically at the bottom and top of the cutting with tape to minimize the entry of air in the cut stem.
- Cover the plastic with an aluminum foil layer followed by wrapping it with brown paper.
- A healthy rooting system will be evident inside the plastic after a few weeks.
- Separate the new plant from the existing plant and place it in the pot for further growth and development.
Grafting is done by combining the plant rootstock having good resistance to the diseases and sticking it with the more attractive and less hardy specimen.
- Grafting requires great care and attention and is a difficult task for inexperienced gardeners.
- The top of the grafted plant is known as scion. Cut the rootstock stem in such a way that it can easily accept the scion stem.
- Seal both these parts with the tape and allow good bonding. After that rooted part can be cut and used for the new growth.
Common Problems of the Hibiscus Tree and How to Treat
The hibiscus tree is adaptable to various fluctuating environmental conditions and stresses. The problem of insect pests and diseases is not severely significant for this plant. Preventing the disease spread and insect pest attack is greatly helpful to boost sustainable growth, and flowering.
Root rotting due to overwatering is a common fungal disease that greatly affects the growth of the hibiscus trees. Rotting of hibiscus leaves also causes leaf yellowing, development of leaf spots, and leaf fall. The problem of root rotting can be avoided by ensuring good drainage and improving the biological health of the soil.
Usual suspects of this plant are common insect pests, and their population can be controlled by using manual, mechanical, and chemical approaches.
The appearance of webs and silky threads on the lower sides of plant leaves is a classic indication of the presence of spider mites. Sometimes these mites also appear as red dots. The problem of spider mites on the hibiscus tree can be controlled with warm water treatment. Early detection of pests is greatly helpful to control this problem on a sustainable basis. Usually, the yellowing of leaves is an indication of weather changes but if the yellowing remains after weather changes it may be an indication of spider mites’ presence. Their populations can also be detected by using microscopes and magnifying glasses. The process of reducing spider mites on the hibiscus plant is as follows.
- Wrap the hibiscus-containing container or pot with aluminum foil.
- Use good quality tape for securing the foil.
- Carefully lay the plant on a side in the clean bathtub.
- Fill the tub with warm water and add some liquid soap. It helps to make insecticidal formulations.
- Leave the hibiscus plant in this tub for 60 minutes.
- Drain the water from the bathtub after this time.
- Allow the plant to stand in the tub and carefully remove the aluminum foil to drain the excess water.
- This warm water treatment kills all the spider mites and their eggs.
- Leaf drop is evident to some extent after this soaking method. So, don’t worry about the minor problem.
Scales can cause significant damage to the growing hibiscus tree and their populations can be eliminated by using a well-prepared mixture of alcohol and baby oil. Apply this mixture with a toothbrush and scrub the pests. Hose down the plant for about thirty minutes and keep the plant away from the sun during this treatment. Allow the plant to stay in the shade for longer periods. This application is ideally helpful on cloudy days for the removal of insect pests.
Thrips are of smaller sizes, and it is very difficult to identify their presence. These can be seen as smaller dots on the lower sides of the leaves. Thrips also fly around the plant and crawl on the foliage. Early detection is critically important for effective control and better management.
These are white-colored crawling insects and leave behind white fuzzy substances. The use of systemic insecticides, soap sprays, neem oils, and essential oils is greatly helpful to control the mealybug infestations on the hibiscus trees.
These are pear-shaped tiny insects under the hibiscus foliage and are of different colors such as yellow, gray, white, green, and brown. The use of organic sprays and manual control is greatly helpful to resolve the problem on a sustainable basis.
Hordes of whiteflies can be seen swarming on the hibiscus foliage. The problem of whiteflies on the hibiscus trees can be controlled in the following way.
- Regularly inspect the leaf surfaces and foliage and carefully identify the stationary nymphs, and whitefly eggs.
- Use clippers for pruning the infected leaves. Carefully dispose of the infected parts to avoid further spread.
- The use of a strong water blast with the spraying hose is helpful to control whiteflies.
- Use this water blast at least once a week to get rid of whiteflies.
- Spray insecticidal soaps, neem oils, and horticultural oils on the plants especially underside the leaves.
- This causes suffocation for the nymphs and significantly inhibits their growth.
- The use of chemical insecticides is also beneficial, but it causes problems for the environment and beneficial insects.
- Growers can also trap the whiteflies by using the sticky yellow traps.
- Apply liquid dishwashing detergent and petroleum jelly on the bright yellow painted cards.
- Place the cards towards the infected hibiscus tree to attract the insects.
Potting and Repotting Hibiscus
- Carefully check the repotting requirements of the growing hibiscus by observing the drainage holes of the containers for the projecting roots.
- Loosen the plant in the pot and lift it in the upward direction to observe the roots in a better way.
- The plant needs repotting if its roots are making tight pot-shaped circles.
- Select a new container or pot with the same diameter and height to keep the present size of the hibiscus.
- Growers can also select larger containers to allow larger and wider growth of hibiscus trees.
- Must provide drainage holes or channels in the containers to avoid root rotting and saturation.
- Add two inches of good quality soilless growing media in the container and moisten it with water.
- Use good growing media with fine drainage capacity and organic matter contents.
- Potting soil and mixes for the hanging plants are ideal growing media for hibiscus repotting.
- Loosen the tree in its first container and gently lift the plant.
- Gently shake it to remove the soil from the older growing medium.
- Slice the roots with a sharp knife for untangling if the roots are winded tightly.
- Trim the broken roots to avoid any problem.
- Place the tree deeper in the new container than the older one.
- Thoroughly water the growing media in the new container to maintain good moistness.
- Add mulch or organic material on the top few inches of the container to support the slow and consistent release of nutrients.
- Keep the container or pot in the bright direct sunlight for some days and then place it back to its original place.
Is a hibiscus tree an indoor or outdoor plant?
Hibiscus trees can be grown in both indoor and outdoor conditions. Outdoor growing plants can easily tolerate fluctuating prevailing conditions and growing mediums. This plant grows and blooms well in well-managed indoor conditions.
Where is the best place to plant hibiscus?
The best place for growing the hibiscus tree is a spot where it can receive proper sunlight and partial shade. The sites having fertile and well-drained soils are also helpful to support better growth and development. The plant can be grown at any place in indoor conditions where growers can manage all growing requirements according to its needs.
What do you do with a hibiscus tree in the winter?
During the winter conditions keep the plant in the unheated basement or garage where the optimal temperature is maintained. Sunlight and warmth can break the dormancy of the hibiscus early. Supply enough moisture during the winter season to support its dormancy. Increase watering frequency and intensity gradually and improve the exposure of the plant to the sunlight by the end of the winter season. Do not fertilize the plant in the winter. Avoid placing the plants near to the heaters and bursts of hot air as it can directly kill the plants.
How to revive a dying hibiscus?
Growers can revive the dying hibiscus plants by using the following care and management measures.
- Keep soil moist and avoid saturation.
- Mist the leaves of growing hibiscus to increase humidity levels in the surroundings.
- Ensure at least 5-6 hours of exposure of the hibiscus plant to the sunlight.
- Replace the poor soil with well-drained and fertile soils.
- Avoid the complete saturation around the rhizosphere to avoid root rotting.
- Avoid windy, and dry conditions in the hibiscus surroundings.
- Avoid overwatering and underwatering.
- Fertilize plants according to the requirements of different growing stages and nutrient provision capacity of growing media.
- Avoid over usage of synthetic chemicals to minimize the stress on plants.
- Use all-purpose fertilizers to provide all macronutrients and micronutrients to the growing hibiscus plants.