Marijuana Leaves Curling – How to Fix Them

Curling marijuana leaves

Growing marijuana may seem to be easy, but sometimes problems arise that can hamper its growth. Then we ask ourselves what might have caused this problem and what we need to do to prevent it.

What is Clawing?

“Clawing” is a term for when cannabis leaves curl up and down. This phenomenon is also called “The Claw.” Clawing or curling is a sign of distress from your plant, and is its way of letting you know something isn’t right. Clawing happens for several reasons, and as soon as it happens you need to figure out what the right solution is.

Reasons for Marijuana Leaf Clawing and Solutions

Overwatering the Plant

Overwatering can be dangerous to your plant’s health. If you are not careful, you could drown your plant. Overwatering can also rinse away helpful microbes. This wet atmosphere can also attract parasites called Pythium, which can cause root rot. This will cause your plant to have claw-like leaves that will tell you it is waterlogged.

To resolve this issue, decrease the watering frequency. Your plant should at least be dry on the surface before you reach for your watering can. One of the most accurate ways to determine if your plant needs water is by using a Moisture Meter. These have the look of a large thermometer that you stick in the plant’s soil, all the way down to the roots. It will give you a reading with a needle on a scale of dry to wet. This could be extremely useful when you can’t tell if your plant is still wet deep in the soil.


Feeding your plant too much fertilizer is also not good. The excess dosage of nitrogen can cause your plant’s to leaves to curl. Overdoing any vitamin or mineral-rich feeding to the plant will cause the leaves to curl.

The best way to cure this is to have a feeding chart to control what you give to your plant. Feeding charts usually come with every fertilizer, sometimes they can be downloaded from the brand’s website. When using fertilizer; it is best to start low and slow. You may increase the dosage over time. Check the leaves every day to see how the plant is responding to the feeding process. The suitable pH is about 5.8pH to 6.0 pH.


Heat stress is hazardous to your plant. It can happen both indoors and outdoors. A sign of this is your plant’s leaves getting burnt. They will turn brown at the tips and curl up. This is a distress signal that you have to take notice of. The average temperature for your plant should not be over 28 degrees Celsius. 

Adjust the temperature of your growing environment accordingly. For indoor growers, it is easy to adapt and to lower the temperature. You may utilize an air conditioning unit to cool down the temperature. Unfortunately, outdoor growers have a little trouble controlling the temperature and exposure to heat. Most cultivators use a screen to shade the plant and keep it cool. 

Colder temperatures are also not suitable for your plants. Cold weather can cause curled leaves as well. Prolonged exposure to cold temperatures, which is less than 10 degrees Celsius, can cause curly leaves and kill your plant. If the temperature is low for indoor cultivation, try adding more grow lights. For outdoor growers, the best way to deal with temperature change is to have an early harvest. The ideal temperature for cannabis plants is 20-28 degrees Celsius. 


If you are planning to reproduce or to breed, it is essential to have healthy parent plants. Healthy parents produce healthy offspring. In the case of an unhealthy parent plant, it may pass on diseases to the offspring that would cause them to grow into a damaged plant. If your plant’s leaves are curling it could be from the parent plant’s genetics. If you have tried all of the suggestions above, this is the likely culprit.


Growing cannabis can be easy and enjoyable, but it also requires much of your attention. If your plant is starting to curl its leaves, this is a sign of distress. You may have to test our suggestions one by one if you are unsure what is going wrong. Regardless, it is important to take action as soon as you notice something to maintain a healthy plant. 

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5 Responses

  1. I have a couple of leaves that have slightly curled up tips on the sides. Is this ok or am I doing something wrong?

  2. – Hello , My boyfriend stuck my plant out in the sun this morning til about ( Its kinda cold ) &&’d Now my leaves are curling down and my top stem is purple. Its was bright and pretty this morning .. Someone please help me ..

  3. The best way to correct light burn is to move you plant away from your light source, usually between eight and 20 inches depending on the watt and lighting type. Temperatures outside of the ideal range of 70 to 80 degrees Fahrenheit also risk discoloration and curl leaves. These oddities are most common in leaves toward the top of the plant and can easily be remedied with a fan (if too hot) or root insulation (if too cold). We also recommend growing plants off a cold cement or tile floor; use a milk crate or stool to raise them off the ground when necessary.

    1. Hey do you know of a particular pest that causes the leaves to curl under where they meet with the other leaf blades on the same leaf?…kinda towards the back of the leaf. I think it’s thrips but i could be wrong. Whatever it is they’re small and to hard to see and they are hiding under where the leaves touch.

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