If you have killed off a hibiscus, I can assure you that you are not the only one! Hibiscus is my favorite flowering shrub, even if the flowers are short-lived, and I learned a lot (through some trial and error!) about how to care for hibiscus and how to identify the problem if it is dying.
It also required a lot of research, as I read every book I could find on hibiscus. I have even been fortunate enough to speak with some specialized growers in my job at a garden nursery, and in these pots, I share with you everything I have learned…
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 caused by a sudden drop in temperature and frost.
As I’m sure you have noticed, hibiscus is very sensitive to environmental change and adapts to a specific set of conditions.
Most commonly, the leaves turn yellow and drop off as a sign of stress, warning that it could die if you do not change the conditions.
However, sometimes, some leaf drops or yellowing of leaves is just a temporary reaction, and the hibiscus revives once it adjusts to the environment or its environmental conditions improve.
There are lots of things can cause your hibiscus to die, so I summarized the main points in this table:
| 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 from 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 requires 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 from drawing up nutrients and moisture. |
| Cold Weather: | Tropical hibiscus (Hibiscus rosa-sinensis) are not hardy and die in cold weather. The optimal daytime temperature for hibiscus is 65°F-75°F and the minimum night temperature of 59ºF. |
| Lack of Nutrients: | Hibiscus in pots may exhaust the available nutrients and turn yellow due to a lack of fertility in the soil. |
| High levels of Phosphorous in the soil: | Hibiscus are particularly sensitive to high levels of phosphorous in the soil which prevents roots from drawing up 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 how I identify the cause of why your hibiscus is dying and how for my methods to revive it…
Table of Contents
Low Humidity and Airflow– Hibiscus Losing leaves or Turning Yellow
Hibiscus are tropical plants adapted to higher humidity levels 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 from losing too much moisture, which would result in the hibiscus dying from drought stress.
I find that low humidity levels are often due to dry weather or windy conditions, which contrast with 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 than outdoors, and the hibiscus drops its leaves in protest.
Your hibiscus should also be kept away from windy areas of your garden or, if indoors, 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 displaying or forming flowers at all, read my article about why is my hibiscus not flowering for how to solve it).
My Tips for Reviving 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 microclimate that mimics the humid conditions of its native environment. The mist on the leaves helps to reduce water loss, which mitigates the effects of draughts and low humidity. It stops dry air, sapping moisture away; the hibiscus may be able to retain more of its leaves.
- Keep the hibiscus in a sheltered area. It needs to be free of constant wind and draughts. Ideally, your hibiscus is in a pot, and you can transfer it to an area buffered from wind in your garden or place it in an area of your home away from any radiators or out of the current from the 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 effects of wind, low humidity, or excessive airflow.
If we recreate the more humid and sheltered conditions the hibiscus should no longer have the stress of losing moisture from the leaves or sudden temperature changes 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.
For indoor hibiscus plants, I tested three different methods of increasing the humidity:
- Misting the leaves
- Using a humidifier.
- Placing your hibiscus pot on pebbles in a tray of water (the idea is that constant evaporation causes humidity).
What I found from my experiment was that my hibiscus lost the fewest leaves when I used a humidifier, with misting the leaves coming a close second, and the tray of water helped the least.
I think the biggest advantage of the humidifier is that it was able to maintain a more constant supply of humidity compared with misting, and the tray of water didn’t actually cause much of a humid microclimate in comparison to the humidifier.
So, my conclusion is to use a humidifier if you have one, or just mist the leaves if you don’t!
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.
Why are my Leaves Wilting, Turning Yellow, and Dropping? (Due to Dry Soil)
As we discussed, hibiscus is a tropical plant that is adapted to living in soils that are consistently moist, yet well-draining and high in organic matter.
If your hibiscus’s soil dries out around the roots then the hibiscus leaves turn yellow and wilt as a sign of stress.
The wilting appearance indicates that your hibiscus is losing more moisture from its leaves through transpiration than 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. This is a survival strategy to prevent the plant from 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. (I find this one is really common with indoor hibiscus).
- The pot is too small and dries out too quickly in the sun. Smaller pots have less capacity for soil and, therefore, less moisture, so they dry out too quickly in full sun. (This happened to me!)
- 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 Save 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. Here are my best tips:
- 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. You can also use a moisture meter, which I find helpful.
- Always water your hibiscus thoroughly rather than 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. So what you need to do to resolve it is water with a generous soak, as this 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 from wilting, turning yellow, and dropping off. I usually use a pot that is 2 or 3 inches wider than the hibiscus.
- Hibiscus should always be planted in soil that has been amended with lots of organic matter. If you are planting hibiscus in garden soil, 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. I personally have the greatest success with leaf mold as it can hold an incredible amount of moisture whilst also being porous enough to allow for good drainage.
- 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 soil’s moisture and maintain the right conditions for hibiscus to thrive. Again, I would recommend using leaf mold due to its ability to retain moisture but I sometimes use normal garden compost too which in my experience still works well.
- Give the hibiscus a spray with mist to increase humidity. Wilting is essentially caused by the leaves losing moisture quicker than the roots can draw it up. By misting the leaves (or using a humidifier) regularly you can create a humid micro-climate which prevents the leaves from losing too much moisture, particularly if the humidity is low or there is a lot of airflow sapping moisture from 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 recovery 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. Planting in poor, sandy soil that lacks nutrients (usually nitrogen) 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.
Due to a lack of nutrients, I typically find that yellow leaves are more commonly associated with hibiscus in pots.
If the hibiscus has been in the same pot for a long time, 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 many nutrients. Fortunately, in my experience, this problem is reasonably easy to solve.
How to Save Yellow Leaves due to Poor Soil
- If your hibiscus is in a pot, it is a good idea to repot it in a larger pot with new potting soil. Larger pots have more soil capacity, and therefore, the hibiscus roots have more access to nutrients. The ideal time to do this is spring, but I have personally done it successfully in the late summer.
- However, if your hibiscus is planted in the ground then adding mulch is a good way to add some nutrients to the soil. I know I’m using mulch as a cure-all solution in these pots, but it’s because I have found it is so effective! I 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 soil’s ecosystem for healthy soil with more available nutrients. I have had the best results when I 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 revive yellowing leaves. I personally recommend a product such as Miracle-Gro, an all-purpose fertilizer. It has the right balance of nutrients at the right concentration for your hibiscus and the slow-release granules, preventing problems with using too much fertilizer, which can leave your hibiscus vulnerable to 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 than 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 temperature changes. Hibiscus requires a minimum nighttime temperature of 59ºF (12ºC). If temperatures are significantly colder than 59ºF the hibiscus can drop all its leaves and die with prolonged exposure to the cold.
It should be noted that two species of hibiscus are commonly sold in garden centers:
- Tropical hibiscus(Hibiscus rosa-sinensis).
- Hardy hibiscus (Hibiscusspp.).
Of course, the tropical species is much more sensitive to cold and in most climates, like mine 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 thespecies of hibiscusthat is suitable for your climate to avoid yellow leaves. My hibiscus I have shown in my photos throughout this article is a hardy hibiscus hence why it is planted outside. I only grow tropical hibiscus as a pot plant.
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.
You can also wrap it in horticultural fleece but, to be honest, from experience, I recommend bringing it indoors rather than risk it dying due to cold.
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 frostbut should be grown in areas of full sun like mine is.
The hardy hibiscus varieties are more resilient and flower for longer than tropical varieties, so if you are concerned about cold weather, always shop diligently at the garden center for hibiscus.
I would have a conversation with the garden center staff to establish the care requirements of the hibiscus you are interested in buying.
I have seen hibiscus sold in supermarkets that do not specify whether it is hardy or tropical, which is why I suspect a lot of people have trouble with dying hibiscus.
However, it should be noted that I have seen sudden temperature changes cause even hardy hibiscus plants to 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 a 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 and drooping leaves with a dying appearance.
Hibiscus requires moist yet well-draining soil. If the hibiscus is in saturated soil, this promotes the conditions for fungal diseases to thrive, preventing the roots from transporting nutrients and moisture to the leaves, turning them yellow and causing them to drop off and die back. So we really have to find that happy medium.
This highlights the importance of getting the balance of soil moisture right for hibiscus.
Some common reasons I see fo soil becoming 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 than boggy. If you water the hibiscus every day then the soil around the roots can be damp which can exclude oxygen from the soil rather than 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.
In my experience, 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 i recommend to 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 feel 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, thoroughly water your hibiscus.
Seasons Changing and Bringing Hibiscus Indoors Causes Yellow or Dropping Leaves
Hibiscus is adapted to a fairly consistent tropical environment, so when hibiscus is 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.
Do not worry!
Hibiscus are notoriously sensitive to changes in the environment, so when the seasons change (particularly when the weather gets cooler), they tend to lose 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 the differing:
- Levels of sunlight (less light indoors).
- Humidity (indoor environments are often much less humid than outdoors).
- More airflow (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 are 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 your 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 microclimate.
- 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 and fewer flowers, and the leaves can turn yellow as a sign of stress.
As I am sure you can imagine, 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.
My 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, what I find works (through some trial and error!) is to gradually expose your hibiscus to more hours of light over a period of 2 weeks to allow it to acclimate.
This can mean moving it to an area of partial shade before moving it to full sun to acclimatize your hibiscus to a higher intensity of light.
For more tips on flowering, read my article, on how to increase hibiscus blooms.
High Levels of Phosphorous in the Soil Causes Yellow Leaves
This is an unusual one that required some research (I spend half my life with my nose in a gardening book!) 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 a concentration.
From my research, I discovered that 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 are that the leaves turn yellow, prevent the hibiscus from flowering and the plant has an overall drooping, dying appearance.
I learned that the 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.
So the solution? 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 salts that result from the frequent use of fertilizer.
To check definitively whether phosphorous is the cause, you can send a sample of your soil off to be tested which is a service available for reputable garden centers and nurseries. I personally haven’t had to do this but if you have, please tell me about it in the comments below!
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 regular watering is essential.
It can take 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.
If you have more problems or stories about hibiscus, please leave a comment below!
Key Takeaways:
- Drought stress is the most common reason for dying hibiscus plants. Hibiscus prefers moist soils and high humidity. If the soil dries out, the humidity is too low, or it’s too windy, then hibiscus leaves turn yellow and drop off because the leaves are losing more moisture than the roots can uptake.
- Hibiscus leaves wilt and turns yellow because of too much water around the roots from overwatering or not enough moisture due to underwatering. Hibiscus requires 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 to promote growth, and flowering and prevent leaves from 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 than 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 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.
