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When cannabis leaves start curling then it means they need help!

Because then they are not in a healthy condition. There are many kinds of bad health conditions of cannabis leaves, like spider mites on cannabis leaves.

And, therefore, you have to look out for the signs that are affecting them and cure them immediately to not let your yield get affected by it.

cannabis leaves curling

Don’t worry, if you are completely new to this.

As in this guide, I am going to share everything about cannabis leaves curling and its solution.

By the end, you will know the solution, cause, and how you can prevent it.

So, let’s get started:

What are the Reasons for Cannabis Leaves Curling?

There are many reasons for marijuana leaves curling.

However, let’s talk about the main factors that cause this:

Nitrogen Toxicity

Nitrogen Toxicity

If your cannabis plant has curled tips with dark color then it might be due to Nitrogen toxicity.

Nitrogen toxicity can also occur if you are providing over nutrients to your plants. And, if not treated timely, this issue can make your garden die, which you never want.

However, cannabis plants indeed need a lot of nitrogen in the vegetative stage.

Though sometimes, growers start providing nitrogen to the plants earlier than the flowering stage, which further leads to nitrogen toxicity.

While the best way to provide nitrogen to your weed plants is to keep the nitrogen level low during the flowering stage and high during the vegetative stage.

Ultimately, you have to keep the balance and keep a regular eye if your plants are showing such signs.


cannabis plant watering

Watering your cannabis plants is the need for their proper growth.

But sometimes, growers do it over.

Especially, the newbies or the growers who don’t have much experience in cultivation.

While the overwatering gives birth to multiple issues if not solved within time.

Apart from making leaves curl, it allows the root rot, and parasites to take place, which ultimately leads to a huge impact on your garden.

And, therefore, overwatering is an ideal place for multiple plant issues.

Though the good news is that overwatering issues can be solved easily.

It is simple:

While watering your plants frequently, you just have to make sure that the soil up to one inch deep is dry.

If it is so, then you are good to go, otherwise, your plant has enough moisture, and you can wait for some time.

This is how the overwatering issues can be prevented.

Also, if you are growing in a hotter region then most likely you have to water regularly. In that case, too, it is always better to check the soil first.

Heat Stress

The ideal range of temperature for cannabis plants is 23 to 28 degrees Celsius (75-to-80-degree Fahrenheit).

And, if somehow, the temperature of the growing area increases from the ideal range, it puts heat stress on the plant leading to the curling of fan leaves.

While ultimately it can also affect the overall health of your plant, which can even reduce the yield and growth of your garden.

Over Fertilizing

Similar to overwatering, over-fertilizing is also not good for your cannabis plants.

It affects the health of plants and leads to marijuana leaves curling.

More than that, it reduces the yield of your garden.

Usually, growers with the intent to increase the productivity of their garden provide excess fertilizer to their plants, which causes nutrient burn.

And, hence, it ultimately leads to unhealthy cannabis plants and also to the curling of tips of leaves.

Therefore, while putting fertilizer in your plants from now, make sure you know the right amount for a specific time.

Just don’t over-provide the fertilizers. It will even decrease the productivity of your garden due to nutrient burn.

Under Watering

Although this is quite an uncommon situation.

Because most serious growers take care of their gardens and water them frequently.

However, somehow, if you are careless about watering your weed plants then this might lead to negative effects on your plants.

Under watering can slow down the growth of your cannabis plants.

And, it is very basic that water helps the plants to make the nutrients reach the right place. Therefore, watering them regularly at the right time is necessary.

So, to avoid this just don’t leave your garden alone for weeks. Underwatering can reduce the plants’ growth and ultimately to the curl of the tips of leaves.

Light Burn

Light burn is a common issue with indoor gardeners.

Though it is not necessarily required that outdoor growers need not be worried about it.

Due to light burn, the cannabis leaves turn yellow and start to curl, which is more likely to happen when you are giving the excess amount of light either indoor or outdoor.

Also, in different growth stages, you need to make sure you are giving the right amount of light.

You need to be aware of when to shift the light and shade schedule from 12/12 to 18/6.

Therefore, to avoid the light burn and also to avoid the cannabis leaf curl, make sure you are giving the right amount of light.

Wind Burn

It is also not a common factor though sometimes it might also occur, and, therefore, you need to be aware of this.

Ventilation in your grow room or area is necessary. However, if you keep your plants on the terrace most of the time then the chances are excessive wind can affect the health of your plants.

Windburn is also can be a factor in the curling of weed plant leaves.

If you are observing something like that, then, ideally you should turn down the fans in grow room for some time.

Also, you can keep your plants inside of your room for a while if you are growing in a windy region.

What Happens After Your Cannabis Leaves Start Curling Up?

Basically, the curling of cannabis leaves is a sign that they are not in a good or healthy condition.

And, therefore, it must be considered by the grower if everything in the growing area is alright.

However, if you don’t pay attention when your plant shows such signs then you can observe these conditions in the upcoming time:

  • Root rot
  • Hosting of different parasites
  • The slow growth of plants
  • Weak branches
  • Decrease in yield
  • Delay in reaching
  • different growth stages
  • Produced weed buds might not have the right amount of cannabinoids

How to Solve the Cannabis Leaf Curling Issue?

As of now, you know what are the different reasons and factors for cannabis leaves to start curling.

Now, is the perfect time to know the solution for the same.

So, let’s get straight into it:

Keep the grow-room environment balanced

The best way to approach a healthy gardening level is to keep everything balanced.

This is necessary especially when you are growing for the first time.

However, if you are completely unaware of how to maintain the right temperature, pH, and humidity in your grow area then you can take the help of different tools in the market.

For instance, if you are growing in a region where humidity is more than required then you can look for dehumidifiers in the market.

Similarly, pH meters, oscillator fans, and nutrient measure tools are there which can help you maintain the ideal growth condition.

Ultimately, this will not only help prevent the curling of cannabis leaves but will also keep the plants healthy to make them more productive.

Don’t overdo anything

Sometimes growers (especially amateurs) in over-excitement give the excessive nutrients or overwater their garden to get the desired results faster.

However, this is what they mistook.

Giving the nutrient more than required can lead to nutrient burn. Similarly, windburn and overwatering issues happen.

So, before you give the extra shot of fertilizer to your plant make sure you know it has digested the previous shot.

All in all, providing anything extra to your plant can lead to some negative consequences and therefore, you should not overdo things.


Yes, research will help you to do the things properly for your specific weed strain.

Do some homework about the strain you are going to grow and know when and how much nutrients, watering frequency, and light are required.

Most likely the previous growers have given their experiences in different grow forums, and that will help you to avoid the mistakes when you will be in action.

This is the most recommended step for a grower who is just stepping into the cannabis cultivation world.

So, from now, do your homework before you start growing.

Then you will know what to do when any situation comes in.


Cannabis leaves curl for multiple reasons. And, in this guide, I have discussed most of the common and rare ones as well.

Also, the final solution will help you to avoid them.

Finally, from now, you will be better prepared for the situation of cannabis leaves curling, and hopefully, now you can easily solve that.

About Joe George
Hey guys, I am Joe G and I provide educational indoor medical home grow guides that demonstrate indoor gardening practices on a budget as organically as possible.

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