🏡|Growing guides|Cannabis Leaf Problems: Find Out About How To Deal With Them In The Article Below

Cannabis Leaf Problems: Find Out About How To Deal With Them In The Article Below

Although weed is considered to be an extremely hardy plant, gardeners often encounter various cannabis leaf problems during the cultivation process. The main marker in this matter is cannabis leaves. In a healthy state, they have a uniform green color and a vigorous appearance. And if any health problems arise, the leaves begin to change their color, shape and become covered with spots.

One of the most important tasks of the professional gardener is to identify marijuana leaf problems. The earlier the cannabis leaf diagnosis is made and measures are taken, the less damage the plant will receive. In this article, I will introduce you to the main weed plant problems, teach you how to recognize them by the appearance of leaves, and offer solutions.

Microclimate Problems

marijuana leaf problems

Violations in the organization of the microclimate, irrigation, and lighting of the plantation greatly affect the well-being of cannabis. Timely identification of the problem will avoid irreparable leaf problems. The main thing is to act quickly and clearly. Diagnosis of marijuana leaf issues is carried out by the appearance of plants.

Indoor Temperature

When buying seeds of a new variety of weeds, always pay attention to the recommended temperature regime. It can be quite different and is due to the genetic characteristics of the species.

Too high temperatures are more common for outdoor cultivation. Lamps heat up the surrounding air, and ventilation does not always cope with heat dissipation. To lower the room temperature, you can install more powerful exhaust fans, replace the lamps with ones that heat up less, or raise the light source higher.

Too low temperatures are especially dangerous when combined with high air humidity.

Light Burn

Cannabis needs bright lighting for normal growth. You should also strictly observe the recommended distance from the lamp to the top of the bush. Light burn is manifested by yellowing and subsequent drying of the leaves. In this case, the veins most often remain green.

If such a cannabis leaf problem is identified, you should immediately raise the suspension height of the lamp or reduce its power.


Overflow is manifested in the form of wilting and curled down over their entire area of ​​leaves. If the situation is too aggravated, then they may even begin to turn yellow. In this case, you should abandon watering for a while and let the soil dry out. After that, water a little, gradually bringing it to normal.

Under watering is manifested by the general wilting of the plant. Leaves become thin and dry from lack of moisture. When watering, the plant quickly bounces back.

Fluctuations in PH

If you do not monitor the acidity of the soil, then you can face such a problem as brown spots on the leaves of weed. Check the acidity of the nutrient solution regularly and adjust the pH if necessary. This indicator is different for each stage of the life cycle.

Nutrient Problems

weed plant problems

New growers often encounter weed leaf problems when adjusting the dosage for cannabis fertilizers. However, many cannabis growers with years of experience can sometimes get it wrong. This is especially true of organic farming when no one knows the exact content of certain components in the composition of the fertilizer. Therefore, it is important to be able to make a marijuana leaf diagnosis and determine the excess and lack of nutrients by external signs. Take your time and always introduce new fertilizers starting at 25-50% of the recommended dose.


Nitrogen deficiency most often occurs during the vegetative growth of cannabis. It is then that the need for this element is greatest. Cannabis leaves problems are expressed as yellowed and wilted lower older leaves. As the progression progresses, the leaves begin to fall off. The plant as a whole develops more slowly and the new leaves are smaller.

If you have noted a lack of nitrogen, then to restore the plants, you should increase the number of nitrogen fertilizers and strictly monitor the acidity of the solution.

Nitrogen surplus appears in the form of darkened and weakened leaves. Exclude fertilizers with a nitrogen component for a while, and after planting returns to normal, introduce them, starting with the minimum dosages.


Potassium deficiency manifests itself in the form of dried and twisted edges of the leaves, turning into yellowish areas towards the middle of the leaf. Fan burdocks most often suffer, but with the progression of the disease, the upper leaves may also be affected. The marijuana leaf problem is that the plant as a whole becomes weak, lethargic and fragile. Lack of potassium most often occurs at the time of intensive growth in the middle of the vegetative phase.

As a cannabis leaf problem chart and fight against the problem, spill the plant several times with pH-balanced water, then add potassium fertilizer and monitor the reaction of the bush.

A potassium surplus by itself is unlikely.


Calcium deficiency manifests itself precisely on young leaves. They become covered with yellow-brown spots, curl up and die off. The edges of the leaves begin to turn brown and dry. The plant noticeably lags behind in development, chlorosis appears.

According to the cannabis leaf diagnosis chart, old leaves will no longer recover, but to stop the spread of the lesion, the substrate should be thoroughly rinsed from salts that block calcium absorption.

A calcium surplus manifests itself with similar symptoms. Leaves weaken, wither, growth is inhibited.


Iron deficiency can be identified by the marijuana plant diagnosis by the chlorosis-affected cannabis leaves. Unlike magnesium deficiency, it is the upper young leaves that are primarily affected here. At first, the base of the leaf brightens, gradually spreading to the edges as the problem progresses.

Use unfiltered, pH-balanced regular tap water for irrigation. General Hydroponics’ CALiMAGic contains a lot of iron, so you can take advantage of it.

Iron surplus appears in the form of a brown rusty hue of leaves and stems.

Cannabis Parasites and Pests

Another source of marijuana leaf disease is insects and other pests. Most often, pests settle on the underside of the leaves, and it is not so easy to notice them if you do not look specifically.

Most likely to meet with the following types of cannabis pests:


marijuana leaf issues

Weed plant problems and cures of aphids. Aphid colonies settle on the underside of the leaves. They prefer lower foliage or young shoots at growth points. Aphids quickly attack the leaves, they become lethargic, turn yellow and eventually fall off. These pests lead plants to death in just a few weeks.

The problem with marijuana leaf diseases in the fight against aphids is not only to eliminate the adults, but also to neutralize all the larvae and eggs of these pests. Just one live specimen will be able to restore an entire colony of aphids in a few days and nullify your efforts.

Start by removing all affected leaves. There is no longer any sense to save them, they will only do more harm. Next, treat the planting with insecticidal soap.

After that, inspect the plants every day and, if new individuals are identified, immediately remove them.

Spider Mite

cannabis leaf problem

These tiny, about 0.5 mm in size, arthropods are almost invisible to the human eye. They can be white, green, gray, or brown. These mites leave small white or yellowish dots on the leaves, which darken over time, and the leaves themselves die off. When these pests have already firmly settled on the bush, they cover it with a thin web.

If you find such marijuana leaves problems, immediately remove the maximum number of pests. It is also better to get rid of the affected leaves. One of the simple and effective remedies is neem oil.

Viruses and Fungi


weed leaf problems

It appears most often due to high humidity in the room and affects the inflorescences or the places of their contact with leaves. Depending on the type of mold, it can be white, gray, brown, black, or even purple.

Tobacco Mosaic Virus

marijuana leaf problem

This virus is highly contagious and can be easily transmitted through touch. That is why hands are the most dangerous vector. Keep them clean at all times and do not start working in the growth box without first washing them with soap.The external manifestation of the tobacco mosaic virus is asymmetric spots of light green, yellow, brown, or brown. Further, the affected surface is covered with tubercles. There are no marijuana plant problems and cures for this virus, and the only way to combat it is to remove the diseased areas. If the lesion is too large, it is easier to get rid of the plant immediately before the virus spreads to other bushes.

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The content on this channel does not form a professional opinion, recommendation, substitute for consulting a specialist, or receiving medical advice. Cannabis is a dangerous drug, as defined in the Dangerous Drugs Ordinance, for all that assumes. Four Hundred and Twenty does not encourage or recommend consuming any substance and will not be responsible for any such use.


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