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Dealing with Cannabis Leaf Septoria

Cannabis leaf septoria

What is cannabis leaf septoria? Leaf septoria on cannabis is, as it sounds, a disease that affects cannabis leaves. Find out how to diagnose and solve these common cannabis pests below.

How to identify leaf septoria on cannabis plant

Cannabis plants are vulnerable to various pests and diseases. On the other hand, leaf septoria is a disease that can seriously affect your cannabis plant’s growth, production and yield. Leaf septoria is a disease that damages cannabis plants and is caused by a fungus or illness. It is most common in humid and moist environments. The indications appear initially on the plant’s center leaves. The patches have darker borders and uneven development in the center, similar to a pimple, but what distinguishes them is that they are all very flat, like small circles. Each spot contains a pathogen receptacle, which shows as tiny black specks in the center of each spot.

Brown spots on cannabis leaves is a sign of cannabis leaf septoria.
Brown spots on cannabis leaves is a sign of cannabis leaf septoria.

Even though the dots are constantly yellow, they will ultimately turn brown. Leaf septoria can also cause circular light brown patches on cannabis leaves. Leaf septoria has evolved into a deadly plant disease that affects the leaves of various plants, particularly cannabis. If not appropriately addressed, this condition can be harmful to plants, causing leaf crushing, poor growth, and eventually affecting the size and consistency of yields.

What causes leaf septoria on cannabis?

Leaf septoria, also named septoria leaf spot or yellow leaf spot, is a plant disease caused by septoria lycopersici, a type of fungus. Leaf septoria often affects plants shortly after they begin flowering and manifests itself first on the underside of leaves. As the disease progresses, it creeps upwards, damaging many leaves all over the plant. Because leaf septoria rarely spreads to fruit, it is unlikely to impact cannabis flowers. If left unchecked, the disease can damage a large amount of foliage. This causes a lot of stress for the plants and inhibits their growth and the size of their harvests.

How to get rid of leaf septoria on cannabis?

Early discovery is critical when coping with leaf septoria, as with most garden pests and illnesses. Keep an eye on your plants during prolonged hot and humid conditions and throughout the early stages of the flowering cycle. Once you’ve recognized the disease, take the following procedures to control it and prevent it from spreading:

Remove infected foliage

The removal of affected leaves is the first step in dealing with leaf septoria. This illness is usually curable if identified early enough by removing all diseased bottom leaves and burning or killing them. However, if the disease has spread to your crops, you should generally avoid this procedure. Removing leaves from growing places weakens the plant and causes the buds to be inconsistent.

Improve air circulation

Adequate air circulation is critical for the cannabis plant and plays a significant role in pest and disease management. If you are growing indoors, boosting air circulation might be as simple as installing an extra fan and leaving some space between your plants. However, if you are working outside, this may be more challenging. Pruning is also an excellent strategy to promote airflow within and between plants. Trim your plants’ highly bushy sections to avoid having leaves contact or resting on top of each other.

Neem oil

Depending on the cause of your leaf spot, you may use neem oil to help combat it. Because neem oil and water can quickly separate, you’ll need a mister to spray all of the leaves equally. Before spraying the entire plant, try spraying just a tiny portion of it to observe how it reacts.

Avoid moisture

Moisture is also an essential factor in the transmission and germination of fungus spores. As a result, you’ll want to stay away from moisture as much as possible. Avoid overhead watering, which will wet the leaves of your plants, and try watering somewhat less frequently to allow the soil to dry out completely. Furthermore, watering early in the day permits the ground to dry out during the day.


Fungal spores frequently spread into soils, where they spend the winter until the circumstances are favorable for germination. First, remove any dead leaves and rake the soil to eliminate potentially contaminated vegetation. After that, thoroughly dry out your soil. Finally, cover the top of your soil with a heavy layer of mulch and water your plants. This will assist in preventing fungus spores from spreading from the soil to your plants.

Remove unwanted plants

Septoria lycopersici spores are commonly found in nightshade and horsenettle. As a result, go through your garden and pull out any cannabis that may be hosting the fungus.

Apply fungicides

Broad-spectrum fungicides and disease control sprays are usually sufficient. Consider using a copper-based fungicide for added protection. In any case, while using any disease control product, remember to strictly follow the packaging directions and try not to get any of it on your buds.

Dealing with leaf septoria outdoors

Leaf septoria typically affects plants immediately after they begin to blossom, and it manifests itself first on the lower leaves. If the illness spreads, it will cause multiple leaves to fall off the plant. Leaf patches can turn yellow, then brown, before dying completely. Leaf septoria rarely develops into berries, although cannabis blossoms are typically undamaged. When the disease is not controlled, it can harm many cannabis plants. This causes a lot of stress on the plants, slowing their growth and diminishing crop output. Leaf septoria is much more common in areas where the weather has been hot and humid for an extended period.

How to get rid of leaf septoria on cannabis?

To begin treatment for leaf septoria on your plant, you must remove every afflicted leaf. Pruning away dead foliage reduces your plant’s exposure to leaf septoria vectors and improves nutrition circulation to new leaves. Depending on how far the disease has traveled, simply removing affected leaves may be enough to prevent it from spreading further.

Stop leaf septoria before it becomes a problem

It is usually preferable to prevent diseases and pests than to treat them when gardening. As a result, adopt these guidelines to avoid a leaf septoria infection in the future:

  • You should rotate plants: Next year, avoid growing your plants in the exact location and growing medium. Fungal spores are incredibly resilient and may return to damage your crops if they are grown in the same regions.
  • Clean your grow environment regularly, especially if you are growing indoors.
  • Make and keep a good environment: If you’re growing indoors, ensure your grow space has the proper temperature and humidity levels. Also, ensure that your plants have sufficient airflow.
  • Regular pruning is required.
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Ed Rushford

Ed Rushford’s impact on cannabis growing is undeniable. Though he tends to focus primarily on 2 areas, plant training techniques and dealing with disease, pests, and other problems, he has offered many insights into how cannabis plants live and grow. That’s not to say that Ed is unfamiliar with the complete life cycle of cannabis, from seed to harvest, but he uses his widespread knowledge to hone in on the minutia and niche areas of growing cannabis. Ed’s goal is to spread knowledge and allow for everyone to become better growers. About this Author

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