Hibiscus are tropical plants that thrive in full sun, moist soil, with consistent warm temperatures. higher humidity and away from wind or draughts.
The reason for a hibiscus dying is usually dry soil, low humidity or excessive airflow which saps moisture from the leaves causing them to turn yellow, drop off and for the hibiscus to die back. Dying Hibiscus is also often because of a sudden drop in temperature and frost.
Hibiscus is very sensitive to environmental change and adapted to a specific set of conditions.
Most commonly the leaves turn yellow and drop off as a sign of stress which is a warning that it could be dying if you do not change the conditions.
However sometimes some leaf drop or yellowing of leaves is just a temporary reaction and the hibiscus revives once it adjusts to the environment or its environmental conditions improve.
Reference table for the most common causes of dying hibiscus:
|Reasons for Hibiscus Turning Yellow and Dropping Leaves:||Causes of Yellow Leaves and Leaves Dropping:|
|Low Humidity:||Most varieties of hibiscus are tropical and require humidity to prevent leaves dropping.|
|Contrast in airflow:||Cold blasts of air in windy areas outdoors, or heat from radiators and air conditioning can all cause yellow hibiscus leaves that drop off.|
|Transitioning conditions between seasons:||Hibiscus are sensitive to changes in conditions and can turn yellow as a sign of stress.|
|Soil too dry:||Hibiscus require evenly moist soil as dry soil causes the leaves to turn yellow, wilted and drop off.|
|Soil is saturated:||Saturated soil excludes oxygen from the soil which prevents roots uptaking nutrients and moisture.|
|Cold Weather:||Tropical hibiscus (Hibiscus rosa-sinensis) are not hardy and die in cold weather. The optimal day time temperature for hibiscus is 65°F-75°F and minimum night temperature of 59ºF.|
|Lack of Nutrients:||Hibiscus in pots may exhaust the available nutrients and turn yellow due to lack of fertility in the soil.|
|High levels of Phosphorous in the soil:||Hibiscus are particularly sensitive to high level of phosphorous in the soil which prevents roots uptaking other nutrients, causing the leaves to turn yellow and the plant to die back.|
|Not Enough Sunlight:||Hibiscus are tropical plants, preferring 5 hours or more of sun and flower best in full sunlight and often die because of too much shade.|
Keep reading to learn why your hibiscus is dying and how to revive it…
Low Humidity and Airflow– Hibiscus Losing leaves or Turning Yellow
Hibiscus are tropical plants that are adapted to higher levels of humidity and fairly stable conditions.
The reason for hibiscus losing leaves is often a reaction to low humidity or excess wind, which saps moisture from the leaves. Hibiscus leaves turn yellow and drop off as a survival strategy to prevent the hibiscus losing too much moisture which would result in the hibiscus dying from drought stress.
Low levels of humidity due to dry weather or windy conditions are in contrast to the tropical conditions in which hibiscus thrive.
The problem of leaf loss because of low humidity is particularly common when tropical hibiscus plants are brought indoors for Winter protection.
The humidity in our houses, or outbuildings tends to be much lower then outdoors and the hibiscus drops its leaves in protest.
Hibiscus should also be kept away from any windy areas of your garden or if indoors, away from anything that can create a draught such as air conditioning or sources of heat that can create convection currents around the house.
(Low humidity is also one of the causes of bud drop and can prevent the hibiscus from display or forming flowers at all, read my article why is my hibiscus not flowering for how to solve it).
How to Revive Hibiscus with Leaves Turning Yellow and Dropping due to Low Humidity
- Use a mist sprayer to spray your hibiscus when indoors. Spraying your hibiscus plant with mist every day or so can create a humid micro-climate that mimics the humid conditions of its native environment. The mist on the leaves helps to reduce water loss which mitigates the affects of draughts and low humidity, sapping moisture away and the hibiscus may be able to retain more of its leaves.
- Keep the hibiscus in a sheltered area. Hibiscus needs to be in an area free of constant wind and draughts. Ideally your hibiscus is in a pot and you can transfer it to an area that is buffered from wind in your garden or place it in an area of your home that is away from any radiators or out of the current from air conditioning.
- Ensure that the potting soil is consistently moist. Water your hibiscus as frequently as required to keep the soil moist (but not saturated). If the roots have a constant source of moisture then the plant is less likely to suffer from the drying affects of wind, low humidity or excessive airflow.
By recreating the more humid and sheltered conditions the hibiscus should no longer have the stress of losing moisture from the leaves or sudden changes in temperature caused by air currents.
This may help the hibiscus to retain more leaves however the leaves may still drop off as hibiscus are very sensitive to changing environmental conditions.
As long as you maintain the best care practices and water your hibiscus well it should recover and new leaves should emerge in the Spring.
Hibiscus Leaves Wilting, Turning Yellow and Dropping Due to Dry Soil
Hibiscus are tropical plants are adapted to living in soils that are consistently moist, yet well draining and high in organic matter.
If the hibiscus soil dries out around the roots then the hibiscus leaves turn yellow and wilt as a sign of stress.
The wilting appearance indicates that the hibiscus is losing more moisture from its leaves through transpiration, then it can draw up from its roots.
This water deficit is unsustainable and with severe drought the hibiscus leaves turn yellow and eventually drop off as a survival strategy to prevent the plant losing any more moisture and dying.
There are several reasons why your hibiscus could be dying due to drought stress:
- Not watering the hibiscus often enough or watering too lightly so the water does not reach the roots properly.
- The pot is too small and dries out too quickly in the sun. Smaller pots have less capacity for soil and therefore less moisture and dry out too quickly in full sun.
- The soil does not retain enough moisture. Sandy soils drain quickly and do not hold onto moisture. Hibiscus grows in soils with lots of organic matter that retain moisture, yet still have good drainage, so that the roots are not in saturated soil.
How to Revive a Wilting, Dying Hibiscus
If your hibiscus stays in dry soil for too long it can die due to drought stress so it is important to keep the plant well watered and amend any conditions that are causing the hibiscus to dry out too quickly.
- Water your hibiscus as often as required, so that the soil is consistently moist. Exactly how often you should water your hibiscus depends on your climate and the specific conditions of it environment, so monitor the soil around your plant to determine whether the soil is moist and if it feels as though the top inch is beginning to dry, give it a really generous soak.
- Always water your hibiscus thoroughly rather then a light watering. If you water your hibiscus too lightly then only the top inch or so of the soil becomes moistened and the water does not infiltrate into the soil to reach the roots. This causes the roots to grow nearer the surface as they try and access any available moisture which increases the hibiscus vulnerability to drought. Watering with a generous soak promotes good root development and prevents wilting leaves.
- Always plant hibiscus in a pot that is at least 12 inches across with the same proportional depth. Smaller or shallow pots contain less soil and therefore retain less moisture, so they dry out much quicker. The hibiscus pot should be at least 12 inches (or as proportionally as big as the plant) to ensure that the roots can access enough moisture to prevent the leaves wilting, turning yellow and dropping off.
- Hibiscus should always be planted in soil that has been amended with lots of organic matter. If your planting a hibiscus in garden soil, this means the planting area should be prepared with compost, leaf mold or well rotted manure to ensure that the soil has the right balance of moisture to prevent hibiscus wilting.
- Give your hibiscus a really thorough watering and add a 2 inch layer of mulch to the soil around your hibiscus (made from compost, leaf mold or well rotted manure) which helps to conserve the soils moisture and maintain the right conditions for hibiscus to thrive.
- Hibiscus should be planted in good potting soil that retains moisture or good multipurpose compost. Compost retains moisture, yet has a porous, areaeted structure that allows for good drainage, which replicates the soil conditions of the hibiscus native environment.
- Give the hibiscus a spray with mist to increase humidity. Wilting is essentially caused by the leaves losing moisture quicker then the roots can draw it up. By misting the leaves regularly you can create a humid micro climate which prevents the leaves losing too much moisture, particularly if the humidity is low or there is a lot of air flow sapping moisture form the leaves.
Once you have established a good watering schedule so that the soil remains consistently moist and you have corrected any environmental conditions that could be causing the soil to dry out too quickly then you have given the hibiscus the best chance at recovery.
Whilst recover takes a long time, new leaves should emerge in Spring or Summer if the conditions are good.
Lack of Nutrients Causes Hibiscus Leaves to Turn Yellow
Hibiscus are relatively heavy feeders and require nutrient rich soil in which to grow. If they are planted in poor, sandy soil that lacks nutrients (usually nitrogen) then this causes the leaves to turn yellow as a sign of stress. The growth of a hibiscus in poor soil is also usually stunted with fewer flowers.
Yellow leaves due to a lack of nutrients is more commonly associated with hibiscus in pots.
If the hibiscus has been in the same pot for a long time then the roots can exhaust the potting soil of nutrients and cause the leaves to turn yellow.
However yellow leaves can still occur if the hibiscus is in sandy garden soil which does not retain as much nutrients. Fortunately this problem is reasonable easy to solve.
How to Revive Yellow Hibiscus Leaves due to Poor Soil
- It your hibiscus is in a pot, it is a good idea to repot the hibiscus in a larger pot with new potting soil. Larger pots have more capacity for soil and therefore the hibiscus roots have more access to nutrients.
- However if your hibiscus is planted in the ground then adding mulch is a good way to add some nutrients to the soil. Add a 2 inch layer of compost, leaf mold or well rotted manure on the soil around the hibiscus which adds nutrients, conserves moisture, improves soil structure and stimulates the soils ecosystem for healthy soil with more available nutrients. Apply the mulch once in the Spring and then again in the Winter for best results.
- Apply fertilizer in the Spring to both potted and planted hibiscus. As hibiscus are such heavy feeders a dose of fertilizer can really help to revive yellowing leaves. I personally recommend a product such as miracle-gro, all purpose fertilizer as it has the right balance of nutrients at the right concentration for your hibiscus and the slow release granules, prevent problems with using too much fertilizer which can leaves your hibiscus vulnerable o disease.
With amended soil and applications of fertilizer the hibiscus should recover from a yellowing appearance with new green leaves.
However, I must emphasize it is important to not use more fertilizer then recommended by the manufacturers as this can cause drooping growth which is more vulnerable to fungal disease.
Cold Weather Causes Dying Hibiscus
Hibiscus are tropical plants that do not tolerate cold weather, frost or sudden changes in temperature. Hibiscus requires a minimum night time temperature of 59ºF (12ºC) . If temperature are significantly colder then 59ºF the hibiscus can drop all its leaves and die with prolonged exposure to the cold.
It should be noted that there are two species of hibiscus that are commonly sold in garden centers:
- Tropical hibiscus (Hibiscus rosa-sinensis).
- Hardy hibiscus (Hibiscus spp.).
Of course the tropical species is much more sensitive to cold and in most climates should be grown in a pot and brought indoors over Winter as even a brief period of cold weather can cause the leaves to turn yellow and drop off.
Therefore it is important to grow the species of hibiscus that its suitable for your climate to avoid yellow leaves.
Whilst tropical hibiscus can drop their yellow leaves after serious cold shock, they can recover if the temperatures stay mild (above 59ºF), or if the plant is brought indoors for protection, with new leaves emerging in the Spring and Summer.
Outside of tropical climates the tropical species of hibiscus struggle to survive if they are kept outdoors all year round.
Hardy hibiscus cultivars can tolerate frost but should be grown in areas of full sun.
The hardy hibiscus varieties are more resilient and flower for longer then tropical varieties so always shop for hibiscus diligently at the garden center if you are concerned about cold weather.
However it should be noted that a sudden change in temperature can cause even the hardy hibiscus plants drop their leaves, however they can recover if you follow the best practices of hibiscus care and new leaves emerge in the following Spring or when the plant has had chance to adjust to new conditions.
Root Rot and Fungal Disease
As hibiscus is a tropical plant that prefers evenly moist soils, underwatering is usually the cause of a wilting and dying hibiscus but too much moisture around the roots can also cause yellowing, drooping leaves with a dying appearance.
Hibiscus requires moist, yet well draining soil. If the hibiscus is in saturated soil then this promotes the conditions for fungal diseases to thrive which prevents the roots transporting nutrients and moisture to the leaves, turning them yellow and causing them to drop off and die back.
This highlights the importance of getting the balance of soil moisture right for hibiscus.
Soil can become too saturated around the roots of your hibiscus because:
- Slow draining soils such as clay soils, compacted soils or boggy areas of the garden can cause too much water to collect around the roots which prevents root respiration and promotes the conditions for root rot, resulting in yellow leaves.
- Overwatering. Hibiscus requires the soil to be evenly moist rather then boggy. If you water the hibiscus everyday then the soil around the roots can be damp which can exclude oxygen from the soil rather then a moist and aerated soil which keeps the hibiscus healthy.
- Pots without drainage holes in the base. Pots without drainage holes, saucers and trays underneath the pots or decorative outer pots without drainage holes in the base, cause water to collect around the roots of your hibiscus, turning the leaves yellow, resulting in a dying hibiscus.
It is very difficult to save a hibiscus plant that has been in saturated soil for a long time as either the roots have become rotten or the fungal disease could have spread throughout the plant so it is highly likely to die back.
However if you scale back the watering, and if your hibiscus is potted, ensure that water can flow freely from the base of the pot by either replacing the pot or removing saucers or trays that are underneath then the hibiscus has some chance of recovery.
Preventing fungal diseases is a much better strategy, so if you have naturally boggy soil in your garden always plant hibiscus in pots as they have more favorable drainage conditions and ensure that drainage holes do not become blocked with compacted soil which can slow down the soils drainage.
Plant hibiscus in compost as it is well draining, yet can retain moisture which emulates the hibiscus soil conditions and balance of moisture in their native environment.
Water the hibiscus so that the soil is moist but not boggy.
The best way to tell whether your hibiscus needs water is to monitor the soil level of moisture but feeling it to a depth of 1 inch. If the soil is still moist then delay watering for a day or so.
If the soil is only somewhat moist and beginning to dry give your hibiscus a through watering.
Seasons Changing and Bringing Hibiscus Indoors Causes Yellow or Dropping Leaves
Hibiscus is adapted to a fairly consistent tropical environment, so when hibiscus are in a home or garden in a climate that has more pronounced season changes, the hibiscus reacts with leaves turning yellow and dropping off as a sign of stress due to contrasting conditions.
Hibiscus are notoriously sensitive to changes in environment, so when the seasons change, (particularly when the weather gets cooler) they tend to loose their leaves.
This often happens when you bring the hibiscus indoors for protection from frost in Winter. The environment of your house contrasts significantly with the outdoor environment.
This can be because of differing:
- Levels of sunlight (less light indoors).
- Humidity (indoors environments are often much less humid then outdoors).
- More air flow (air conditioning and sources of heat can cause draughts and fluctuating temperatures, which cause leaves to drop).
- Watering (if the hibiscus is outdoors it benefits from rainfall whereas indoors the environment and air is dryer and the demand for water can increase, so you have to water more often to prevent dehydration).
Usually some yellowing of the leaves or some leaf drop is to be expected at different times of the year and the hibiscus can bounce back, with new emerging growth in the following Spring or Summer.
However it is important to follow the best practices when caring for your hibiscus if you are bringing it indoors to mitigate losing leaves and yellowing such as:
- Mist the hibiscus regularly to create a more humid micro-climate.
- Place the hibiscus in the sunniest window of your house with at least 5 hours of sun.
- Keep the hibiscus away from draughts, air conditioning, air currents and away from sources of heat.
- Water the hibiscus as often as required so that the soil is moist but not saturated.
With diligent care the hibiscus should revive the following Spring with new growth and flower buds.
Not Enough Sunlight– Hibiscus Not Growing
Hibiscus grows best and displays more flowers in full sunlight, growing well in 5 hours of sun or more. If your hibiscus is in dappled light or full shade, then the hibiscus can have poor growth, fewer flowers and the leaves can turn yellow as a sign of stress.
This tends to be most problematic for indoor hibiscus, due to lower levels of light in houses.
If there are low levels of sun then the hibiscus has less energy to display flowers and the growth appears spindly weak and the leaves either turn yellow or drop off.
The only solution is to find the sunniest window of the house to place your hibiscus to give it a chance to revive.
If you have planted your hibiscus in the garden in a shadier spot then I recommend trying to allow more light by cutting back any overhanging tree branches, or you may have to transplant your hibiscus to a large pot and place it on a sunny patio area for it to recover.
Hibiscus is very fussy about sudden changes to the environment and it can drop its leaves if it is moved into full sun from an area of shade suddenly, so for potted hibiscus it is best to slowly expose the hibiscus to more hours of sun over the course of two weeks.
This can mean moving it to an area of partial shade before moving it to full sun so acclimatize your hibiscus to a higher intensity of light.
For more tips on flowering, read my article, how to increase hibiscus blooms.
High Levels of Phosphorous in the Soil Causes Yellow Leaves
Hibiscus plants are very sensitive to the level of phosphorous in the soil, which is usually the result of using fertilizer too often or in too high concentration.
When phosphorous accumulates in the soil it can make other nutrients such as insoluble and prevent the hibiscus roots from uptaking iron in the soil.
The symptoms of excess phosphorous in the soil is that the leaves turn yellow, prevent the hibiscus from flowering and the plant has an overall drooping, dying appearance.
Accumulation of phosphorous in the soil is usually to due to overzealous applications of fertilizer, particularly any fertilizer that contains a disproportionate amount of phosphorous which are often marketed as ‘bloom boosters’, designed to increase flowering.
Scale back the use of any fertilizer if you suspect phosphorous is the cause for your hibiscus leaves turning yellow and water it regularly.
Watering your hibiscus regularly can help dissolve accumulated slats that result from frequent use of fertilizer.
To check definitively whether phosphorous is the cause then you can send a sample of your soil off to be tested which is a service available for reputable garden centers and nurseries.
It is difficult to have a build up of phosphorous in the soil if you are using a quality, well balanced fertilizer such as miracle-gro all purpose granular fertilizer as the granules release nutrients slowly into the ground and the product has the right amount of nutrients at the right concentration for plants such as hibiscus to bloom.
There are also fertilizers with a lower concentration of phosphorous that are available from garden centers and online which can help to revive the hibiscus, but regularly watering is essential.
It can takes a long time to revive hibiscus due to phosphorous sensitivity so patience is required but they can eventually recover and diligently check any labels to avoid any fertilizer that has a high concentration of phosphorous which should be listed on the product.
- Drought stress is the most common reason for dying hibiscus plants. Hibiscus prefer moist soils and high humidity. If the soil dries out, the humidity is too low or its too windy then hibiscus leaves turn yellow and drop off because the leaves are losing more moisture then the roots can uptake.
- Hibiscus leaves wilt and turn yellow because of too much water around the roots from overwatering or not enough moisture due to underwatering. Hibiscus require well draining, yet consistently moist soil. Boggy soil causes root rot resulting in a dying hibiscus whereas dry soil causes wilting, yellowing leaves.
- Hibiscus requires full sun. If the hibiscus is in too much shade it can stop growing, the leaves can turn yellow and the hibiscus may not display any flowers. Always place hibiscus in an area of 5 hours or more of sunlight promote growth, flowering and prevent leaves turning yellow.
- Too much airflow or wind can dry out hibiscus leaves causing them to turn yellow and drop off. Hibiscus requires high humidity and should be sheltered from wind or draughty areas. Spray the leaves with mist regularly to emulate the humidity of the hibiscus tropical native environment.
- To revive a dying hibiscus ensure the soil is moist rather then saturated, mist the leaves to increase humidity and ensure your hibiscus has at least 5 hours of sunlight. Once you have adjusted the conditions to suit the hibiscus, new growth should emerge in the Spring and the plant should recover.
- Plant hibiscus in well draining soils and in pots with drainage holes in the base. Hibiscus requires moist yet well draining soil. If the roots are in saturated soil, then this is the cause of your dying hibiscus as damp soil promotes the conditions for fungal disease and root rot.