Asking yourself “Why are my Hibiscus leaves turning yellow?” Our comprehensive guide covers all the reasons for Hibiscus yellow leaves, what to do about them and how to prevent them.
With expert gardening help, you can keep these beautiful tropical plants growing, thriving and adding color to your world.
Hibiscus Plants are Sensitive to Environmental Stress
There are 200 species of Hibiscus, all of which originate from the islands of Madagascar, Fiji, Hawaii and Mauritius, and all bringing a touch of these island paradises to your yard.
There are also a few perennial Hibiscus species native to North America, known as rose mallow.
Perennial Hibiscus do well in zones 5-9 (typical temperature range of 21 degrees Fahrenheit to -1 degrees Fahrenheit), while tropical Hibiscus need warmer temperatures (flowering well at 60-90 degrees Fahrenheit).
If you live in a colder zone, rather plant your Hibiscus in a container that you can bring indoors and keep warm during cold months.
Hibiscus grow up to 15 feet tall and thriving in containers as well as yards, they are a firm favorite with gardeners all over the world.
No matter what type of species you have, always put in mind that they are all sensitive to environmental stress, diseases, and as well as pests, which can all result in Hibiscus yellow leaves.
Why are the Leaves of My Hibiscus Plant Turning Yellow and Falling Off?
The most common reasons for Hibiscus leaves turning yellow is too little or too much water.
The soil should drain well, and the plant should be watered frequently to keep the soil moist or the leaves will turn yellow and die.
If the first inch of soil is dry, the plant needs to be watered. If the soil does not drain well and the plant’s roots sit in the water for a long time, the roots will start to rot. Causing Hibiscus leaves to yellow and the plant to die.
You can add bark, compost and sand to poorly draining soil to improve the quality.
Environmental Factors That Affect Hibiscus Plants
Hibiscus plants respond quickly to abrupt changes in the environment, including air moisture, soil, fertilizer application, and as well as temperature.
When the days start to become shorter, and the temperature becomes colder, this will trigger the leaves to turn yellow and drop.
For perennial Hibiscus, you should cut the plant to about 6 inches high above the ground so that you get good re-growth in spring.
Watering Hibiscus Plants
Hibiscus plants are tropical and enjoy moist soil, so they are not drought tolerant plants. They need regular watering but shouldn’t sit in water, as this will cause yellow leaves on Hibiscus as the plant begins to rot. S
wamp Hibiscus can grow in conditions that are boggy, which means that they can grow at the edge of the water, but the majority of these species need soil that drains well when regularly watered.
If you let the soil become too dry, the leaves will start turning yellow and crisp as they die. In winter months, water your Hibiscus less often as overwatering can turn the leaves yellow.
This plant is a heavy feeder, which means it loves fertilizer and needs plenty of nutrient in order to grow and flower.
You can use a granular or liquid fertilizer rich in potassium and nitrogen but low in phosphate (a 7-1-2 or 12-4-8), feeding regularly according to manufacturer instructions in the spring and summer.
It is important not to feed your Hibiscus during winter, as the plant will go dormant and unused fertilizer in the soil can burn the roots, causing the plant to weaken and the leaves to yellow and die.
Pruning Yellow Hibiscus Leaves
Should I Remove Yellow Leaves from Hibiscus?
Once you have discovered the source of your Hibiscus yellow leaves and applied the right solution, it is a good idea to remove all the yellow leaves and any dead or unhealthy growth.
Use a clean, sterilized pruning clipper and wash it after use, especially if your Hibiscus had a pest, fungal or bacterial problem.
Do You Deadhead Hibiscus?
This is not as important to Hibiscus care as it is for other plants. In fact, it can prevent a late show of Hibiscus blooms and delaying next year’s flowers!
They actually have what is known as self-cleaning flowers – dropping blooms and replacing them on their own accord.
If you want your Hibiscus to stay a certain size or shape and to flower well, prune it in early spring and feed it well with a fertilizer rich in potassium.
FAQ About Caring for Hibiscus Plants
How Do I Know If My Hibiscus is Overwatered?
Hibiscus plants like moist but not waterlogged soil. You can tell if you are overwatering because the plant is wilting, and the leaves are turning yellow and falling prematurely but the soil is wet (and has been for days).
The Hibiscus may also get edema, which is water retention. This looks like bumps and blisters on the undersides of the leaves. It will also suffer from root rot, which is when the roots decay, turning brown and mushy.
Are Coffee Grounds Good for Hibiscus?
Hibiscus plants are heavy feeders that like slightly acidic soil, so coffee grounds are a great organic fertilizer for them.
You can pour old, cold coffee onto the soil along with the grounds, although they do work best if they are combined into your compost so that they break down well.
Why are My Hibiscus Buds Turning Yellow?
This is usually a symptom of a pest infestation – usually spider mites, aphids, whiteflies or mealybugs.
Insecticidal sprays do usually help, but there are also effective, natural remedies like Neem oil, solutions of dishwashing soap and water, and encouraging beneficial predatory insects.
Is Vinegar Good for Hibiscus Plants?
Vinegar will lower the PH of your soil, so if you have neutral or alkaline soil, you can use it to create the slightly acidic PH that Hibiscus plants thrive in.
Mix one cup of vinegar with a gallon of water, soaking it into the ground around the base of the plant rather than onto the leaves.
Test your soil with a soil test kit before you do this an keep testing each month so you can keep the soil between PH 6-7.
What is the Best Fertilizer for a Hibiscus Plant?
Hibiscus are heavy feeders that need lots of nitrogen and potassium but low in phosphate, so the best fertilizer for Hibiscus is a 7-1-2 or 12-4-8.
It can be liquid or granular fertilizer and should be applied with plenty of water in spring and summer but not through winter.
Is Miracle-Gro Good for Hibiscus?
Yes, as long as you are using a formula that is high in nitrogen and potassium but low in phosphate, like a 7-1-2 or 12-4-8.
Is Epsom Salt Good for Hibiscus?
Epsom salt is rich in magnesium and sulfur, which help plants to absorb nutrients more effectively and produce healthy chlorophyll.
Hibiscus plants enjoy a good dose of Epsom salts as they are heavy feeders, and it helps promote plant health as well as plentiful blooms.
Leaves Turning Yellow May Be Due to Disease
Diseases tend to spread all throughout the plants even before the leaves start to turn yellow. Typically the fungal diseases of Hibiscus are because of Phyllosticta, Cercospora, and Cladosporium fungal species.
This starts as white spots that turn grey, stunting the growth of your plant and is often the reason for Hibiscus leaves turning yellow and dying. It is very common in environments where there is a lot of humidity.
Although it’s not usually fatal, you want to deal with this issue before it stunts your Hibiscus and spreads to affect other plants.
You can use Neem oil, a spray of baking soda, water and vegetable oil, and a commercial fungicide (a last resort, as these are harmful to the environment and not always effective on established powdery mildew).
If a Hibiscus is overwatered or living in boggy, poor-draining soil, the roots become infected with fungus and start to rot. One symptom of this is Hibiscus yellow leaves.
The best thing to do is to improve the soil quality, adding lots of organic compost and bark to help improve drainage. You should also reduce watering and only water when the first inch of soil appears dry.
Bacterial and Botrytis blight
This bacteria causes discolored and spotted flowers as well as discolored shoots and yellow leaves on Hibiscus.
Prune away any affected growth and prune back plants that are crowding the Hibiscus to create better airflow.
It’s also advisable not to over-feed your Hibiscus and to avoid over-watering, as the increased humidity encourages bacteria growth.
One of the most beautiful parts of a hibiscus is their flowers. The reason behind this is because they are colorful and large, which is very inviting to pollinators and as well as to unwelcome insects, including root knot nematodes, and scale insects.
For people who don’t know, scale insects are feeding on plants by piercing their stylets into the soft tissue of the plant. The stylets will then act as straws to help the sap be drawn up.
A smaller number of scales may have little to no effect to your hibiscus, but once they start to multiply, the leaves will start turning yellow and prematurely drop on the ground.
The nematodes, on the other hand, are worms that look like eels that are small. They usually feed on the plant’s roots.
They will then cause knotty galls, which will act to impair the function of the plant. This will then turn the leaves to start wilting and turn yellow.
When using a fungicide, it would be best to read the labels if it is safe for the plants that you have, since there are Hibiscus species that are sensitive to chemicals.
Pests that Attack Hibiscus Plants
Many people plant Hibiscus shrubs for their large and colorful flowers – but these bold blooms don’t just attract people; they attract insects too!
In addition to beneficial insects and pollinators like bees and butterflies, these flowers can also attract pests like spider mites, aphids, mealybugs and whitefly.
These are small, spider-like insects that live off the sap in plant leaves. They appear as tiny white or yellowish insects and leave behind a distinctive soft, silken webbing on the plant leaf.
Hibiscus leaves yellow and the plant will wither and die, so it is essential that you treat a spider mite infestation quickly with a general-purpose insecticide or Neem oil for about 64 days to kill the adults and eggs.
Another sap-sucking insect, these tiny flying pests look like their name – small, white flies.
You can effectively prevent and treat these infestations by encouraging natural predators like ladybugs, green lacewings and pirate bugs, and by feeding your Hibiscus well in spring and summer.
Insecticides don’t work on whiteflies, but you can place reflective items (foil, CDs, etc.) around the plant to discourage them or use Neem oil.
The most common sap-sucking pest is the aphid, and you can spot them as clusters of small insects on tender growth. They drop a sticky substance called honeydew and are often accompanied by ants who consume this liquid.
You can introduce predator insects to your garden to eat the aphids (ladybugs and lacewings) and plant fennel, aster, cosmos, larkspur, verbena, hollyhock, dill, yarrow and mint to draw aphids away from your Hibiscus.
Garlic and onion plants will drive aphids away. You can also use Neem oil or wash the aphids of with a mix of liquid dishwashing soap in water.
Insecticide is not recommended as this tends to kill predator bugs, so the harmful pests usually increase in number!
These insects are easily identifiable from the hard, cotton-like cottony or waxy cover to protect themselves once they’ve settled on a plant. Like aphids, they also produce honeydew.
Adults need to be removed by hand and, while encouraging beneficial insects does a lot to control mealybugs naturally, you may also need to use Neem oil.
Lack of Sunlight Affects Hibiscus Leaves
Another reason why the leaves of the Hibiscus are turning yellow is that the plant isn’t getting enough sunlight. As topical plants, they need at least 6 hours of sunlight each day.
This can be indirect sunlight, although they do best in direct sunlight. You will find that you have fewer blooms the more shaded your Hibiscus is.
Now You Know What Causes Hibiscus Yellow Leaves
We hope you have enjoyed this guide and found out not only what caused your Hibiscus yellow leaves, but discovered an effective solution to restore your plant!
The most common reasons for Hibiscus leaves turning yellow are overwatering your plant, lack of sunlight, a pest or disease, or underfeeding your plant.
Remember, these beautiful tropical plants need 6 hours of sunshine, constant moisture (but mustn’t get waterlogged), and regular feeding in spring and summer with a 7-1-2 or 12-4-8 fertilizer. Happy growing!