Hibiscus performs well in tropical and subtropical climates. This is why we can grow it outdoors in warm climates. In colder regions, we usually grow it in pots or containers to overwinter hibiscus plants indoors. There are multiple reasons for yellow leaves on hibiscus. In this article, I will tell you why the leaves turn yellow on hibiscus.
Note: The yellow leaves due to overwatering, underwatering, pest attacks, or stress, all have different symptoms (if you look closely). Yes! the leaves turn yellow but you can learn how to distinguish them from this article.
If your healthy hibiscus plant started showing yellow leaves in the fall or winter, no need to worry that much. Wait until the winter passes. Most of the hibiscus varieties go dormant in colder months.
I know you can't be relaxed until you can confirm the yellow leaves are due to dormancy. This is how you can check it:
The symptoms: Some or all of the leaves will turn yellow, but the leaf stalk will remain firm and not become mushy. You can use your nail to scratch a stem. The inside should be green. This means the plant is healthy and is under dormancy.
The older leaves turning yellow is also a natural process of the plant.
The reasons and treatments for hibiscus leaves turning yellow
The major reasons are listed below and I will explain each of them separately with the corresponding treatments.
- Overwatering
- Imbalanced fertilization
- Too much heat with less watering
- Pests
Overwatering
Due to overwatering the green leaves will start turning yellow.
You may notice yellow shades on green leaves. Like part of a leaf will be yellow and you can see the green part at the same time.
Shaking the plant, the leaves might fall off easily.
How to treat: You must check if the water drainage is good or not. Excessive water in the soil can cause root rot. I usually mix perlite or sand in the soil to keep the water-draining system good.
For potted plants, you can place the pot vertically on the ground for a day. Do not water until you see the top inch of the soil if dry.
Imbalanced fertilization
Hibiscus plants are heavy feeders. That means they can tolerate fertilizer better than most of the other plants.
But we need to understand what type of nutrition the hibiscus plants demand.
They love fertilizer that contains nitrogen and potassium more than phosphorus.
Make sure that the potassium is higher than phosphorus.
For example:
- 10-4-12
- 17-5-24
- 12-4-18
These are the NPK ratios.
A lower nitrogen ratio can cause leaf diseases like yellow leaves and yellow foliage.
Treatment: To treat the yellow leaves faster you can consider foliar spray that contains more nitrogen and potassium.
You can also provide normal fertilizer in the soil. (Ration mentioned earlier)
Note: If you provide a larger amount of Phosphorus, it can block nutrient uptake. This is a major reason that the plant can't absorb nitrogen and leaves turn yellow.
Too much heat with less watering
In warmer climates, this is a very common reason for hibiscus leaves turning yellow.
Hibiscus plants are usually drought tolerant but that does not mean that they perform well in dry soil.
You need to water when it demands water. Otherwise, you can witness this type of leaves:
The leaf stalk will not be mushy this time.
Treatment:
If the plant is potted, bring it inside or under shade for a couple of days and water thoroughly. (Never forget about the water drainage) Make sure the pot has working holes at the bottom.
Pests
I will not talk much about pests in this article as there are multiple pests that can attack your hibiscus plants.
Though, I have something for you: Get rid of mealybugs on hibiscus
