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Hibiscus leaves are generally a lovely shiny green, so when they start turning yellow, it is quite noticeable, and it can cause you to worry about the health of your plant. There are many causes that can turn the leaves yellow, some need to be dealt with right away, or your plant could die.
So, why do Hibiscus leaves begin to turn yellow?
There are many reasons why the leaves of a Hibiscus plant will turn yellow, including overwatering or underwatering the plant, a nutrient deficiency in the soil, too much or too little sunlight, temperature changes, changing the plant’s location, attacks from certain pests, and even chemical shock.
Having your favorite plant’s leaves turn yellow can be a depressing thing, but it is not always your fault, and usually, the problem can be fixed. Let us see how to fix the yellowing leaves problem for your Hibiscus plant.
Why Would the Leaves of a Hibiscus Plant Turn Yellow?
Hibiscus plants can have their leaves turn yellow due to stress in their environment; these stresses can be several things, some of which you may not even think about.
Below is a list of reasons why your plant’s leaves are turning yellow that you can go through and see which ones are relevant to your plant. So, let us have a look at what could cause Hibiscus leaves to turn yellow.
1 – Watering Problems
Hibiscus plants are known for being thirsty plants, especially the tropical Hibiscus plant varieties. Your Hibiscus plant will require daily watering in the summer months, sometimes even needing to be watered twice a day if the temperature reaches over 80 degrees Fahrenheit.
If your Hibiscus is underwatered, especially in hot temperatures, this can cause the plant’s leaves to turn yellow. However, your Hibiscus plant’s leaves will also turn yellow if you water them too much.
When the temperature drops and your plant begins to go dormant, you need to stop watering it as frequently as this can cause your Hibiscus plant’s leaves to turn yellow. Both underwatering and overwatering your Hibiscus plant can cause the plant’s leaves to turn yellow.
The only way to try and avoid these two situations with your Hibiscus plant is to only water the plant when needed. You can tell if your Hibiscus plant requires water by keeping an eye on the plant’s soil moisture.
So, in the hotter summer months, water the plant enough to keep the soil moist but ensure that the soil is never soggy after watering. If your Hibiscus plant gets waterlogged soil, this can lead to more problems than just yellow leaves.
Rather underwater your Hibiscus plant than overwater it until you find the perfect amount of water your plant needs. In the colder winter months, you only water your plant to keep the soil slightly moist, so the plant does not dry out completely.
2 – Nutrient Deficiency
Something that quite a few people miss when it comes to the care of their plants is the nutrient levels in the plant’s soil. This is easy to miss as you cannot see them and see how much of each nutrient is left in the soil or what nutrient there is too much of in the soil.
But knowing the nutrient levels in your Hibiscus plant’s soil is a key aspect in ensuring your plant’s health. If your Hibiscus plant’s leaves are turning yellow, this can indicate a nutrient deficiency in the plant’s soil.
If your Hibiscus is potted, you need to ensure you are repotting your plant as soon as it shows the signs of needing a repot. For example, if the roots of your Hibiscus plant are growing out of the pot’s drainage holes, your plant needs to be repotted.
If you leave your plant in this condition for too long, it will easily deplete the soil of nutrients, which can cause the leaves to turn yellow. If your Hibiscus plant is planted in your garden, you need to get a soil test done to see if there is a nutrient deficiency in the soil, and if so, which nutrient it is.
Once you know what nutrient is missing or lacking in your Hibiscus plant’s soil, you can go and buy a fertilizer with a high concentration of that nutrient and feed your plant.
3 – Sunlight
Sunlight is another reason why your Hibiscus plant’s leaves may be turning yellow. Hibiscus plants are known for having a somewhat complicated relationship with sunlight.
With a Hibiscus plant, the more leaves it has, the more sunlight the plant needs to sustain all of them and keep them healthy. If your plant has many leaves, then the leaves that are in any form of shade will be the leaves that will turn yellow.
Even if you keep your Hibiscus plant in a location where it gets good sun, some of its leaves can still turn yellow if the leaves are overcrowded, as some leaves will block sunlight from reaching others. This problem is something that is easy to fix as you can just do some selective pruning with a few leaves or move the leaves around so that they are all getting good sunlight.
However, with Hibiscus Plants, you need to find a good balance between sunlight and shade, as the shade can also be good for your plant. Hibiscus plants need about six hours a day of direct sunlight, but the sun will burn their leaves if they get more than this.
So, if your Hibiscus plant is getting too much sunlight and too little sunlight, the leaves can turn yellow. A simple way to tell these problems apart is that if the yellow leaves are not spotty, it results from too little sunlight.
4 – Temperature Change
When your Hibiscus plant is deprived of water, its leaves will turn yellow, but if the temperature rises, this will increase your plant’s need for water, meaning you will need to water it more frequently.
Hibiscus plants prefer their temperatures to be maintained between 60- and 90-degrees Fahrenheit; anything above or below this temperature range will stress your Hibiscus plant. Any drop or increase in temperature needs to be addressed as soon as possible, or your Hibiscus plant’s leaves can start turning yellow.
If you cannot control your Hibiscus’s temperature, you need to help your plant in other ways. For example, if you are in the middle of a heatwave and temperatures skyrocket, you need to water your Hibiscus plant more frequently, which will prevent or fix yellow leaves caused by this issue.
Alternatively, you can place your plant in the shade to help alleviate the hot temperature effects on your Hibiscus plant.
However, if your Hibiscus plant’s leaves are turning yellow due to cold temperature stress, you can apply a layer of mulch to your plant’s topsoil and shelter the leaves with a plant covering until the cold weather subsides.
Something related to the temperature that can also affect the leaves of your Hibiscus plant is the wind. You need to keep your Hibiscus plant out of the wind and cold drafts as this will cause the leaves on the side of the plant facing the draft or wind to turn yellow.
5 – Location
If your Hibiscus plant is kept in a pot, then moving the plant around is part of the plant’s care. For example, when the plant is in its dormancy period, you need to bring the plant indoors and keep the plant in a dark, cool location for a few months.
Then as the plant begins to come out of its dormancy period, you need to cut it back and place the plant in a sunny window for a few hours every day, and you resume your regular watering schedule for the plant.
Then once spring arrives in full force, you move the plant outside again. If your Hibiscus plant looks wilted, its leaves are turning yellow, or the plant stops blooming for a while, this can be due to the stress the plant goes through with all this movement.
This is due to the plant needing to adapt to new and different environments every time it is moved. This is natural, and your plant should get back to normal if you leave it in one location for a longer time.
6 – Pests
A reason why your Hibiscus plant’s leaves may be turning yellow is that your plant may be under attack by a pest. The pests that could be attacking your plant causing the yellow leaves include Thrips, Spider Mites, Aphids, Whiteflies, Mealybugs, or Japanese Beetles.
These pests are the ones in particular that will make your Hibiscus plant’s leaves turn yellow, as these are the pests that suck the sap out of your plant. When this happens, it can cause your Hibiscus plant to act like it is underwatered as it is dehydrated from lack of sap.
However, this is not the only damage these pests can do to your plant. There might be bumps where the pests have bitten into your plant, along with discoloration at the bite site.
These sap-sucking insects like to live and hide out on the underside of your Hibiscus plant’s leaves. So, if you think you have your Hibiscus plant in the right growing conditions for your plant to thrive, but you still notice yellow leaves on your plant, you need to check the leaves for signs of pests.
Treating a pest infestation may be your only task to stop the leaves from turning yellow, but you should act fast as these pests can kill your Hibiscus plant if they are left unchecked.
7 – Dormancy
Hibiscus plants, just like all plants, go through active and non-active growth periods. For the Hibiscus plant, the active growing period is in the spring, summer, and fall months.
When the seasons start to change at the end of autumn, the Hibiscus plant will begin to enter its dormancy stage. When the plant starts to go dormant, its leaves will start turning yellow, and they will eventually fall off the plant.
During this time, as the plant goes dormant, you need to reduce the amount of water you are giving your Hibiscus plant and allow your plant to rest for the winter.
8 – The Wrong Soil
This problem is closely related to watering issues that can occur with your Hibiscus plant. If your plant is not in the correct soil, your Hibiscus plant’s leaves can easily turn yellow.
Hibiscus plants that are potted require plant pots with many drainage holes that can allow excess water to drain from the soil. Just like the plant pot needs to be well-draining, so does the soil you plant your Hibiscus plant in.
You need to ensure your Hibiscus plant is in well-draining soil that is loose and well-aerated as well. If your plant’s soil does not have these qualities, then the plant is more susceptible to being overwatered as the excess water drains slower, which can cause your Hibiscus leaves to turn yellow.
The best type of soil to keep your Hibiscus plant in are loam and sandy loam soils. Soils that are more on the clay side will need to be amended as these soil types retain too much water, and they drain slower, causing your Hibiscus leaves to turn yellow.
9 – Chemical Shock
Chemical shock is not a common problem that you will have with your Hibiscus plant, but it can happen. Chemical shock happens with Hibiscus plants if you overuse pesticides or use the wrong pesticide for your Hibiscus plant.
Alternatively, if you spray the plant with a pesticide in the midday heat, with the hot sun pelting the plant, all of these can lead to chemical shock and the plant’s leaves turning yellow. So, if you have used pesticide recently on your Hibiscus plant, this could be the cause.
But if you used the correct dosage and the right pesticide and sprayed the plant in the morning, then the leaves turning yellow are probably caused by something else on this list.
There are several causes that you can look into if your Hibiscus plant’s leaves are turning yellow. Some of the reasons are natural, and you do not need to worry about them, while others can be a big cause for concern as they can kill your Hibiscus plant.
The best way to find the right diagnosis is to go through the list one by one and see which causes are relevant to you and then fix them one at a time. Good luck with your Hibiscus plant!