Tropical hibiscuses are relatively easy-to-care-for plants, as long as the conditions are right. But what if your hibiscus leaves start curling? It can be an indication that something is negatively affecting your plant.
The most common causes of hibiscus Leaves Curling are inadequate moisture, nutrients, sun, temperature, or soil pH. Additionally, the reason could also be external stress like disease or pests. Proper watering, indirect sunlight, temperatures of 60-95°F (15-35°C), and attentive care can ensure optimal health and growth for your hibiscus plant.
It isn’t easy to pinpoint the origin of your hibiscus plant’s curling leaves, so you will need to carefully examine your plant to figure out the problem. This article details the different causes of curling, symptoms to look out for, and how to fix the issue at hand.
Causes of Hibiscus Leaves Curling
Depending on the type of deformation, you need to find out the cause of your plant’s ailment and the solution to heal your plant!
Underwatered hibiscus will start curling to keep the moisture inside their leaves. Conversely, overwatered plants may also curl, and wilt as it can lead to root rot.
The damaged root system can not intake water and nutrients and the leaves will show symptoms like underwatering. So it’s essential to keep the balance just right.
Hibiscus leaves curling up usually signals a lack of water while downward curling leaves indicate too much water. However, if you’re unsure, you can check for the following:
If you’ve underwatered your plants, the soil will be dry and might pull away from the pot. The leaves might brown and become crispy and light, and the lower leaves will yellow and curl. Lastly, their growth will be stunted along with brittle crisp stems.
On the other hand, if you’ve overwatered your plants, the soil will be wet. The leaves will feel soft and limp, possibly with browning edges.
There could also be yellowing leaves accompanied by new growth. In addition to these symptoms, there might be mildew, mold, or fungal growth, which can cause disease in your plants.
If you’ve underwatered your hibiscus, completely submerge the pot underwater for twenty minutes to breathe life back into your plant. If your plant is not potted, increase the watering frequency– NOT the watering amount- to two or three times a day.
If you’ve overwatered your hibiscus, do not water it for one or two weeks in order to let the soil dry. You can examine it by sticking your finger two inches deep into the potting mix to check. Also, decrease the usual watering amount after the soil has dried out.
If the overwatered hibiscus got itself root rot (you need to check the roots) then it may be difficult to salvage the plant.
But you can save it if the infestation is limited to some parts of the root. Just trim off the infected part and treat it with a copper-based fungicide. Then repot it into a new pot with fresh soil mix.
Temperature Stess Cause Leaves Curling
Hibiscus are tropical plants that can tolerate cold temperatures. These plants like temperatures of around 60-95°F (15-35°C). Any temperature below 50°F (10°C) will cause stunted growth, curling leaves curl and shedding.
Oppositely, constant temperatures of above 100°F (38°C) can cause heat stress in your plant—this heatwave results in over transpiration in your plant.
Transpiration is when leaves release water from their leaves. Over transpiration or the release of too much water causes curling, withering, and wilting.
If temperatures are cold, move the plant indoors and place them somewhere sunny. That’s why it’s better to grow your hibiscus plant in a container, no matter the species.
A potted plant gives you the ability to move it indoors in the colder months in order to protect it from dropping temperatures.
If the temperatures are too hot, move the plant to a well-shaded area and mist the leaves to help cool it down and take the stress of the roots.
Plants require sunlight. Depending on the plant type, they’ll require either direct, indirect, and no sunlight. As for hibiscus plants, they need indirect sunlight for optimal growth.
Incorrect types of lighting will have different effects on your hibiscus plant. Direct sunlight can cause burns, curling, and yellowing at midday, while too little light will cause the plant to drop leaves.
Ensure you place your plant somewhere that isn’t directly in the sun at midday or entirely in the dark. You could put your plant by east or west-facing windows or windows with opaque blinds that block a few of the sun’s rays.
Soil acidity is commonly overlooked by novice growers, but could negatively affect your plants’ water and nutrient intake. Hibiscus grows best in slightly acidic soil (between 6.5 and 6.8 pH).
Soil pH affects the solubility of minerals and compounds, meaning how easily they dissolve in water. Acidic soils cause toxic minerals like aluminum and manganese to be more soluble.
In contrast, with alkaline soils, the necessary minerals like iron and phosphorus are unavailable in the required quantities. This type of soil can lead to nutrient deficiencies in your plant.
Before planting, check your soil’s pH with a pH strip or any other testing kit.
If the soil pH test shows that the pH is higher than 7.5, use sulfur, iron sulfate, manganese sulfate, or aluminum sulfate to lower it. If the pH is less than 5.5, you can apply an agricultural lime or dolomite.
Wait two weeks and retest the pH of the soil to ensure that conditions are ideal before you plant your hibiscus.
Without proper nutrients, your plant’s leaves won’t be able to grow correctly. Mineral deficiencies can cause leaf curling and stunted growth in your plants, so it’s essential to give them the correct nutrients. For optimal development, most garden plants need:
- Nitrogen (N)
- Phosphorus (P)
- Potassium (K)
- Sulphur (S)
- Calcium (Ca)
- Magnesium (Mg)
However, hibiscus plants CAN NOT process phosphorus like other plants. Instead, this mineral can be toxic to your hibiscus.
Phosphorus can get added into the soil through fertilizers or even the water used for watering. A plant with too much phosphorus is not recoverable!
Hibiscuses require a high amount of potash, a medium amount of nitrogen, and minimal amounts of phosphorus as well as trace amounts of Iron (Fe), Copper (Cu), and Magnesium (Mg).
On the other hand, overfertilization can cause browning, leaf curling, wilting, heat stress, and more. Most of these symptoms mimic overwatering.
If your plant experiences nutrient deficiencies, fertilize it with the proper minerals. You can mix your own or buy a suitable fertilizer for hibiscus plants. Check the label for the minerals mentioned above. The type of fertilizer can be either water-soluble or chelated.
If you’ve over-fertilized your plant or have excessive build-up, leach it out of the soil by watering it for a long time. This process draws the fertilizer down, away from the roots. Just make sure the pot has good drainage.
Also, if it’s on the surface, you can remove the fertilizer that sits on top of the soil. Don’t remove more than a quarter-inch of the earth below it.
Remove any rotten or wilted leaves to help your plant focus its energy on healthy leaves.
There are three common types of diseases your plant might experience. Infected soils or improper acidity can cause diseases in your hibiscus plant.
- Brown spots with yellow halo indicates fungal disease, eventually which cause yellow leaves or black spots. Fungul attack reduces the leaves ability to photosynthesize and eventually it will curl to save energy.
- Dieback disease can adversely affect the branch or stem of your plant. Dieback disease is usually caused by a fungus that enter through a crack or rip in one of the branches or stem of your plant. This is easy to detect because you’ll notice only one of your plant’s branches or stems will be adversely affected.
- Root rot is the worst and hardest to detect because it’s underneath the soil. However, plants with rotted roots contain absorb water or nutrients, causing your plant’s leaves to curl and wilt. If you smell a foul odor from the soil, this might indicate root rot, which occurs from overwatering.
If you have suspicions, you could also take out your plants and check the roots. Healthy roots should be white, while rotted roots will be soft mushy, slim black, grey, or brown roots.
Some diseases are more harmful than others. If left without treatment, your hibiscus will get sicker and you’ll need to help nurse it back to optimal health.
For chlorosis, remove any of the affected leaves. Removing these dying leaves keeps the plant from wasting energy on leaves that will probably fall off anyway.
Instead, it helps them focus their energy on the leaves with the best chance of recovery. Generally, the plant will repair itself with proper care.
For dieback disease, simply cut the affected areas with a clean pair of scissors. Make sure to disinfect them afterward for future uses. By removing the infection, it stops the spread to other parts of your hibiscus
Lastly, for root rot, you can help the affected hibiscus by cleaning the roots. Clean the roots by running water gently over them and remove all the rotted roots with sharp scissors by cutting just above the damaged area. Afterward, re-pot the plant.
Please note to sterilize the scissors afterward to avoid infecting your other plants!
For all the diseases, you should transplant the plant into new clean soil with suitable pH and fertilizers. The fresh potting mix will ensure there are no harmful microbes in the soil.
And, just in case, don’t water your plants with hard tap water. The minerals in the water will increase the acidity of the soil.
Insects and pests are the biggest threat to your hibiscus plant if they are outdoors. Various insects can cause your plants stress, curling, and yellowing leaves.
- Aphids are common tiny insects that suck out your plants’ nutrients, causing the leaves to turn yellow and curl. Aphids are green or reddish-brown bugs that can be hard to detect until they become more prominent.
- Worms and caterpillars on the leaves of your hibiscus are usually harmful to your hibiscus. If this occurs, a white layer will develop along the leaf veins.
- Spider mites are small and red that leave thin cobwebs on your plant. Yellow dots will form on the leaves where insects eat. The affected foliage will then gradually turn yellow and dry up.
- Japanese beetle larvae will eat the roots of your hibiscus plants. They are generally laid in the soil and eat more significant roots as they grow. The destruction of your plant’s root will cause it to be unable to absorb nutrients, especially if the larvae become very big.
Always check the underside of leaves. This area is where most pests will rest on the plant.
You can check and buy chemical solutions to get rid of pests; however, chemicals could have adverse side effects for you and your plant.
Natural solutions include washing the pests off by gently running water over the plant and rubbing the bugs off the leaves.
Alternatively, you could also introduce natural predators like ladybugs into your garden; however, this isn’t viable for most people.
I, personally, use a mixture of one-third neem oil and two-thirds water. Neem oil is a natural pesticide, and its oiliness helps keep worms and caterpillars off. Additionally, it is suitable for your plants and gives them a nice sheen.
Spray the mixture on your plant and brush away the pests with a toothbrush. You can regularly spray your plants if they are prone to infestations.
Why do Hibiscus Leaves Curl after Repotting?
Hibiscuses like more compacted roots; therefore, you might find yourself repotting your plant more often than other household plants. However, being uprooted and moved can instigate transplant shock in your plants.
Transplant shock occurs with improper repotting. The unexpected conditions stress your plants and cause their leaves to curl and wilt.
Generally, you want to keep conditions the same for your plants, meaning the soil and lighting should be the same as previously used. When moving your hibiscus, do so carefully not to injure the roots.
Other problems might originate from leaving your plant out too long before repotting. Exposing the roots to the air for too long or transplanting at the wrong time can be the source of your leaves curling or wilting.
Make sure to never repot your plant during the spring as they are most sensitive before they bloom. Additionally, place your soil into your new pot before removing your hibiscus from its old pot.
How to Prevent Hibiscus Leaves Curling?
Prevention is more manageable than treating. You can prevent your hibiscus leaves from curling by making sure conditions are perfect for the plant.
Prevention starts with choosing the right sized pot, which for hibiscus is a well-draining one. Afterward, choose a good soil mix with materials like composted bark, perlite, coco coir, and peat moss. It’s essential to make sure the soil is porous so that the hibiscus roots get enough oxygen.
Once you’ve found a suitable container, choose a perfect spot for your hibiscus. Hibiscus need indirect sunlight, and they do not like wind. So, place the potted plant somewhere with indirect sunlight and not near the AC vents or fans.
Lastly, make sure you’re watering your hibiscus properly. Never use too much water or dump it directly into the soil, instead of water your plants with a sprinkler, watering can, or pouring it through your fingers.
In the summer months, hibiscus requires more frequent watering; however, water your plant much less frequently in the winter month.
Curling leaves or leaf deformation can be a sign of many problems. However, as long as you ensure the proper conditions for your plant, it will grow wonderfully without problems.
After this article, you’re now armed with the proper knowledge to diagnose your plant and help nurse it back to peak health!