Cannabis leaf curl can’t vocalise a cry for help, but they can send signals that let you know things aren’t right. A curling leaf or claw can indicate many problems, including heat stress, nutritional deficiency, pH imbalance and pest infestations.

If a cannabis plant is overexposed to heat stress it may start exhibiting symptoms like leaf curling and yellowing of the foliage. These symptoms are a response to the stressor and the plant is trying to protect itself by curling up or drooping. Heat stress is often combined with other symptoms such as nutrient burn, which usually shows up as crispy brown leaf tips.

Cannabis Leaf Curl: Understanding and Managing This Common Issue

A cannabis plant may show signs of a nutrient deficiency if it is overexposed to too much fertilizer or to a nutrient that isn’t suitable for the plant’s stage of growth. Some of the common nutrient deficiency symptoms include:

Overwatering can suffocate your plants’ roots and cause nutrient uptake issues. It can also lead to diseases such as root rot or other fungal infections.

To prevent nutrient deficiencies or overwatering, follow the recommended watering methods for your particular grow medium. Water your plants enough to allow the top soil to dry out a bit between waterings, and don’t overwater them. Also, ensure that your growing medium has the right pH levels to maximise nutrient uptake and minimise deficiency symptoms. Lastly, regularly inspect your cannabis plants for signs of pests and diseases such as spider mites, thrips or fungus gnats.