Why Do Indoor Plant Leaves Curl?

Why Do Indoor Plant Leaves Curl?

Houseplants are generally stress-free and low maintenance. With the proper lighting, adequate watering and ample fertilization, it should thrive without any issues.

But what do you do when your plant does get sick?

When the leaves of your indoor plant start to discolor or curl it’s time to give your plant some attention.

When your plant’s leaves start to curl, you can be sure that there is something wrong. For indoor plants, it could be anything from pests, insufficient lighting, heat stress, nutrient deficiencies or even watering. It’s about balancing all these factors to ensure the best for your plant’s growth.

What is Leaf Curl?

Leaf curling is usually caused by a variety of fungi, bacteria of deficiencies in the plant. When this occurs, the number of leaves, fruits, and flowers tend to reduce in number or in worst cases, kills the plant entirely.

By knowing the signs, symptoms and possible causes, you can choose the correct form of treatment or remedy to extend your plant’s life.

Causes of Leaf Curls and How To Treat Them
Most issues that do occur with indoor plants are environmentally caused. This means the root of the problem is the light, temperature, humidity or water.


There is such a thing as excessive lighting and insufficient lighting when it comes to indoor plants. It is important to research your plant to know which is the best spot to place it in.

A. Insufficient Light

When your plant does not get enough light, the stems get thin and flimsy. The leaves are small, pale in color and may have a curl as well.

Treatment: Indoor plants do not really need direct sunlight, however in order for photosynthesis to start they would need some source of light. The best thing to do is place a light source above your plant to help it grow.

B. Excessive Light

Plants, in general, are supposed to thrive in the light. However, since indoor plants are accustomed to lower light or dim spaces, too much can release free radicals that absorb more energy and eventually destroy the plant. Aside from evident rotting of the plant, the leave starts to curl and brown.

Treatment: Avoid exposure to direct sunlight. Move your plant to a shadier area that is not completely devoid of light.

Heat Stress

When the leave starts to lose color and curl inward, this is indicative of too much heat. Placing plants near heat sources like space heaters or radiators causes rapid evaporation. Room temperatures of 80o and above are not advisable for indoor plants.

Treatment: If they cannot be moved to a cooler area, you could install a fan to cool down the room, or a humidifier to add more moisture into the air.


Plant leaves also tend to curl and become discolored when there are nitrogen, phosphorus or potassium deficiencies. All of which can be avoided with the proper supplements.

Treatment:The simple remedy for this is to add specialized fertilizers for which deficiency your plant is suffering from.


Under and over watering can be bad for indoor plants as well. It’s all about balance. Take into consideration the type of plant you get and know when to water it. If you are too busy with routine watering, it would be best to get aquatic plants since they need the least attention.

A. Overwatering

This is the most common problem with indoor plants which is evident from drooping leaves that curl downward.

B. Underwatering

When the soil is completely dry and the leaves start browning and curling at the tips, they will eventually wilt and fall off. This shows the last few phases of your plant’s life.

Treatment: When watering your plant, you would want to check the soil. Remember, it must be moist not too wet and definitely not dry. Indoor plants would not need daily watering. Depending on the type, you can do with watering it once a week.


One of the most common causes of leaf curling is insect infestation due to improper care. If you have many plants, be sure to check them regularly to know if they may have bugs, and try to control the problem before the bugs spread to their neighboring plants.

Treatment: The first thing to do is isolate the plants infected and treat them according to the insect they are infested with. When they are all back to health, you may include them with the others.

Common Pests for Indoor Plants

There are a variety of pests that infest your plants causing the leaves to curl. Most of these insects carry viruses, bacteria or fungi responsible for the curling for your plants. Here are some of the most common pests:


These tiny pests come in different colors and cluster on the underside of the leaf. They survive by sucking the sap from the leaves which causes the yellowing and curling of the plant. Aphids are also able to transmit viruses between different plants. They multiply fast, at around 12 to 20 offsprings per day, once you catch them on your plant, isolate the plant as soon as possible to stop the spread.

Fix: Aphids have a waxy protective exoskeleton, by spraying them with potassium salts the waxy shell weakens and kills the insects. This should be done weekly until you no longer see aphids or signs of them on the plant.


Aside from the leaf curl, Thrips also cause the leaves to dry to a crisp and eventually crumble. These insects look like pieces of threads and come in brown and black colors. They suck the sap out of the plant and eventually dry them out. They are very hard to see because of their minute size.

Fix: Spray the plants affected with neem oil. This solution would stunt the Thrip’s development. Repeat the treatment at least twice or thrice every 7 to 10 days. This ensures that eggs and hatchlings will not survive either.


Although not exactly like spiders, they are closely related. They have four pairs of legs, no antennas and have a sharp tooth that is able to pierce through the plant to suck out nutrients. By doing this, it causes discoloration on the leaf and eventually curls the edges when the sap is about to run out.

Fix: Spray the plants with a pesticide specifically for arachnids or crawling insects. The formula in these pesticides would be enough to kill both the eggs and larvae. Remember to spray this in moderation.  

Other Plant Deficiencies

Nutrient deficiencies are quite hard to diagnose, but here are a few symptoms to look out for and the remedies you can do in order to keep your plant healthy.

Nitrogen Deficiency

This deficiency affects the oldest leaves first. When newer leaves are not getting ample nutrients, the plant re-distributes it from the already existing leaves. For fruit-bearing plants, it is quite normal to see this deficiency since it would put more energy onto the fruit it bears.

Symptoms: The older leaves lose its green color, become soft and curl inwards. This eventually falls off.

Remedy: Apply a high-nitrogen fertilizer onto the soil. This is quickly absorbed and highly efficient. In order to avoid nitrogen deficiency entirely. Include an amino-acid supplement as part of your routine.

Phosphorus Deficiency

Similar to nitrogen deficiency, the first affected by this deficiency is the older leaves, and it eventually reaches the rest of the plant when left untreated.

Symptoms: Older leaves look bluish and have an extra shine, the leaves curl downwards and would have bronze spots.

Remedy: When the symptoms are already showing, the best remedy would be to use bone-meal supplements with high phosphorus content. To avoid this deficiency, proper climate control is needed. In cooler temperatures, plants inhibit the intake of phosphorus. Maintaining a temperature within 65o to 75o F is ideal.

Potassium Deficiency

Whenever the plant starts budding or flowering, you can be sure that it would distribute essential nutrients to those specific parts, potassium is taken from the rest of the plant and centralized onto the flowers.

Symptoms: The plants look like they have been burned, due to the fact that the outer portion of the leaves are dark brown in color and curled. Whereas the veins and surrounding areas stay green.

Remedy: Use high-potassium fertilizer whenever you have flowering or fruit-bearing plants. You should also check the pH of the fertilizer, anything above or below range would not be absorbed by the plant. For soil based plants the ideal pH would be 6.0 to 7.0, whereas aquatic plants are more adapted to pH levels within 5.5 to 6.5.

It is important that you know the specifics of your plants needs to ensure their healthy growth.

Different varieties and species would mean different modes of care.

Being able to give your plant what it needs, when it needs it, eliminates your worry and just gives you a better, happier houseplants overall. 

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