Cannabis leaf burn: triggers and prevention

Causes and prevention for burnt cannabis leaves

Modified on: 20/09/2022

Hemp leaf burn: find out what it is, how to recognize it and prevent it

There is always something to learn about the world of hemp growing. However, even when hemp growers pay attention to every step of the cultivation process, they can still come across a few inconveniences from the moment they plant the cannabis seeds to flowering. One of the most frequent is leaf burn.

What causes this problem?

How can you remedy the appearance of burnt cannabis leaves?

If you are a marijuana enthusiast who would like to find out the primary triggers of this phenomenon, read on because, in this article, we will tell you about the top three.

Here’s what you should know.

Cannabis leaf yellowed

Wind burns: what it is, symptoms and prevention

One of the most common causes of cannabis leaf burns is wind.

We have always said that hemp plants like to be in a ventilated environment, which is ideal for preventing moisture build-up; however, the plants can become stressed when the wind hits too hard. The signs caused by too much wind are called ‘windburn’ and can occur in outdoor and indoor crops due to fans.

This problem occurs mainly in the latter case. In closed structures, space is often limited, and fans have to be placed too close to the plants. What’s more, while outdoors the wind comes and goes, it is present every day and at all times in grow rooms!

Windburn is easily recognisable. They usually affect the leaves most exposed to the air, which end up bending down. To illustrate this, think of large, wrinkled fingers.

To prevent this problem from occurring, it is essential to plan the space as early as planting the marijuana seeds. In advance, you have to calculate both the space needed for each plant to grow and the space for the necessary equipment.

For example, for the same amount of space, you will be able to plant more dwarf auto-flowering plants than Sativa plants, which are much bulkier.

It is also a good idea to use adjustable fans with various settings in indoor cultivation.

Read also: Cannabis fungus: what they are and how to prevent them?

Light burns: what they are, symptoms and prevention

Burned leaves in cannabis plants can result from excessive exposure to light.

In this case, we are talking about artificial light, the lamps installed in indoor cultivation. When the lighting system is placed too close to the plants, both the light and the heat become too intense, and the plants suffer.

Light burn and heat stress in hemp can be recognised because the leaves on the upper part of the plants turn yellow and brown, while those further away from the lamps remain green.

This phenomenon only occurs in indoor cultivation, as the sunlight radiates differently outdoors.

To prevent this, it is advisable to use dimmable or not too bright lights or place them further away from the plants. In addition, thanks to fans, you should make sure that the indoor temperatures are not too high (better to keep them around 25°).

Burnt hemp leaves

Nutrient burns: what they are, symptoms and prevention

Another cause of leaf scorch is overfeeding.

We all know that cannabis plants need an adequate supply of nutrients to grow. But anyone who thinks that giving them more fertiliser than expected will speed up their growth is sorely mistaken.

Too much nitrogen, phosphorus, and potassium are not suitable for the plants; it weakens and stresses them until they show symptoms.

The symptoms we are talking about are precisely nutrient burns, recognisable by the fact that the leaves of hemp plants turn brown first at the tips and then over the whole surface. In addition, the leaves tend to roll up and become brittle after darkening.

To prevent this problem from occurring, it is essential to follow the standard nutrient doses and ensure that the plants are adequately lit. If the plants are well lit, they absorb many nutrients and vice versa.

To solve this problem, firstly, the supply of nutrients to the plants should be stopped, and secondly, the levels of minerals in the substrate should be accurately measured.

If the soil is more than saturated with nutrients, it might be a good idea to flush it with pH-balanced distilled water. Subsequently, however, it is essential to ensure that the water drains away and does not remain stagnant at the bottom. Otherwise, one problem will turn into another: root rot.

Read also: Cannabis mother plants: what they are, advantages and selection

To conclude

This short article discusses the leading causes of cannabis leaf burn and the best prevention tactics.

Hoping that this informative article has satisfied your curiosity, we invite you to visit our online shop: SensorySeeds.

In our shop dedicated to selling collectable cannabis seeds, you can find many of the best genetics.

Choose from our wide range of quality weed seeds to complete your collection: feminized seeds, auto flower seeds, fast growing weed seeds, there is something for every taste! 

We look forward to seeing you on!