The avocado is a flowering plant that possibly comes from Mexico, particularly its south-central part. Known as Persea Americana scientifically, avocado is a healthy fruit that provides you with tons of nutrients.
Their popularity has led to many garden enthusiasts growing their avocado plants. But it is not easy as this plant needs pure water and balanced fertilizer to prosper.
The avocado leaves curling is one of the most common problems you’ll encounter growing it. Today we are discussing what causes avocado leaves to curl up and how to prevent it.
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Why Do Avocado Leaves Curl?
Avocado leaves curl because of underwatering, overwatering, low humidity, lack of nutrition, overfeeding, temperature stress, and diseases.
Causes of Leaf Curling in Avocado Plants
Avocados are very sensitive plants. You have to be very precise about watering and fertilizing it.
For it to grow well, the avocado needs plenty of sunlight. If your avocado leaves are curling, there could be several reasons.
Let’s learn about some causes.
1. Root Rot because of Overwatering
We understand if your first reaction to the situation is to reach for the watering can to water the plant. However, overwatering causes more damage.
While some plant leaves curl up because of underwatering, avocado leaves also curl when they are overwatered.
The excess water surrounds the root blocking out the air, so they suffocate and die. These dead roots can get root rot, which later spreads to healthy roots as well.
All of this cuts the water supply to the leaves, which then curl up.
Underwatering is the simplest explanation for avocado leaves curling. Since avocados are subtropical plants, they thrive in humid environments that have plenty of water.
You have to keep their soil moist – moist, not wet. If they remain underwatered, their cells start to collapse, causing the leaves to curl, droop, and appear crispy.
3. Low Humidity
Low humidity is perhaps the least apparent cause of avocado leaves curling, yet it is the most common in homegrown avocado plants.
Dry air drains the moisture out of the leaves causing them to wilt and curl before turning brown and finally falling off.
It is challenging for a plant to survive in such conditions so take action quickly.
4. Lack of Nutrition
Undernutrition in plants manifests itself in many ways. And leaf curling is one of them.
Potted plants are more prone to lack of nutrition because they have a limited medium to grow in. So, they keep absorbing the available nutrients.
But as time passes, all the nutrients in the soil deplete, leaving them wanting.
If you’ve had your avocado plant for a while and never fertilized it, lack of nutrition could be the cause of its leaves curling. It is a sign your plant isn’t getting enough phosphorus, potassium, nitrogen, or magnesium.
5. Overfeeding with Fertilizer
As mentioned above, an avocado plant needs phosphorus, potassium, nitrogen, and magnesium, along with traces of other nutrients to thrive. So, it is essential to feed it with a suitable fertilizer.
But, too much of something, even if it’s good, can cause harm.
High mineral content in the soil causes root burn. It stops the roots from functioning correctly, and the plant starts suffering.
They turn limp and weak, with yellow leaves that curl, of course.
6. Temperature Stress
The environmental temperature of 60–85 °F (15-30°C) is ideal for avocado growth. Too much warm or cold, and it will exhibit signs of distress.
In a cold environment, its systems cannot function adequately. It either becomes dormant or dies if it is very cold.
Scorching temperature, on the other hand, affects it at a cellular level. Its cells cannot cope with the heat and begin to collapse.
7. Diseases and Infections
Avocado plants and trees are prone to different kinds of infections and diseases. Root rot is one of them.
It shows itself in curling leaves that make the plant look thirsty. And if you mistakenly give it more water, the condition aggravates.
Another fungal disease that causes avocado leaves to curl is powdery mildew. It starts as a layer over the surface of the leaf.
But as it progresses, the leaf begins to curl and falls off.
Remedies to Treat Curling Avocado Leaves
These are some of the common causes of curling avocado leaves. If your plant is suffering from one or more of these issues, it will show it with curling leaves.
Here is how to remedy these problems and help your plant survive.
Underwatering and Overwatering
First, make sure that the plant is truly underwatered. Using your finger, check the soil’s moisture. If the upper two inches are dry, it needs more water.
Water it deeply at the roots. It’s better to do so every few days instead of every day.
Another way to make your avocado plant thrive is to plant it in a well-draining medium. This way, even if you end up overwatering it, the extra water drains away instead of surrounding the roots.
Even though avocado plants love water, be cautious still when you water them.
Lack of Nutrition and Overfeeding with Fertilizer
Phosphorus, magnesium, potassium, and nitrogen are some nutrients that an avocado plant needs. They are plentiful in a general-purpose fertilizer that has a 20-20-20 ratio.
To avoid both these avocado leaves curling issues, feed it every 2 weeks with a plant fertilizer (the general one will do) with a 20-20-20 ratio.
Remember to feed it during growth season. Stop when winter starts as the plant’s growth slows down as temperatures drop.
As spring rolls in, repot the plant in a fresh medium to give it a nutritious boost.
If temperature stress is causing your avocado leaves to curl, pay attention to where you put it. Moving between different temperature conditions harms its growth.
Draft from window cracks or heat from the radiator can also take its toll.
Choose a suitable place to grow your plant, one that has a consistent environment. And if you have to move it, allow it to adapt to the new location.
Try putting it in its new place during the day and back at night to help it assimilate.
Avocado plants thrive at a humidity level of around 70–80% but can’t survive if the humidity levels are down to 45%.
To maintain the humidity level above 45%, you can also increase humidity by having multiple plants grow together in the same room.
Diseases and Infections
Avoid overwatering your avocado plant at all costs. But also prevent it from becoming too dry.
Both these conditions encourage fungal growth that causes avocado leaves to curl. They become deadly for the plant.
You can also use fungicides to kill off the disease as well. But without improving the plant’s condition, it is useless.
Keep an out for invading infections. Also, keep the surface of the potting medium free from debris.
An avocado plant is susceptible. You have to take good care of it to make it thrive.
Give it a healthy environment and plenty of sunlight, and your plant will soon bloom into a strong tree.
Frequently Asked Questions About Why Do Avocado Leaves Curl
How often should you water the avocado plant?
Avocado plants like water, but be cautious when watering them. Underwatering and overwatering both pose significant risks to its integrity. To err on the safe side, better water it once every few days.
Do avocados like direct sunlight?
Avocado plants simply love direct sunlight. Even if you are growing one indoors, place the plant in the brightest spot you can find. They can tolerate some shade but cannot survive long without sunlight.
Daniel has been a plant enthusiast for over 20 years. He owns hundreds of houseplants and prepares for the chili growing seasons yearly with great anticipation. His favorite plants are plant species in the Araceae family, such as Monstera, Philodendron, and Anthurium. He also loves gardening and is growing hot peppers, tomatoes, and many more vegetables.