What the Yellow Spots on Cannabis Leaves Tell You

Leaf yellowing or technically known as leaf septoria is very common among cannabis plants that can cause harm if unattended. Unfortunately, no strain of cannabis is not safe for this plant disease. Leaf septoria or yellow spots on cannabis leaves is a deadly plant disease that affects your cannabis’ plants foliage. It’s a common disease among plants, and very common to cannabis. 

If not addressed properly, leaf septoria will damage your plants significantly and will eventually destroy your foliage. To help everyone, we’ve prepared a post to take a look at this disease and how to fix it and prevent it from infecting your plants. 

What is this Disease?

Leaf septoria is also known as yellow spots on cannabis leaves. It is a type of plant disease that is caused by a fungus called Septoria lycopersici. This type of fungus thrives on garden weeds and dead foliage. It can spore and spread easily through contact even with garden equipment. 

This can create great damage to your cannabis plants and can greatly disrupt the growth of your cannabis plants. 

Leaf septoria is known for its spots that are usually yellowish and brownish in the color that can be found on the lower and upper portions of the leaves. These spotting can have a round shape with darker brown patches on it while it has a greyish middle. It usually grows up to 6.5-millimeter. 

This disease affects plants that just started its flowering stage. It usually starts to form on the lower portion of the leaves. As it starts to spread and develop its way up, it can also affect other plants in its surrounding area, especially those that are in its proximity. 

The affected leaves can turn yellow and brown and will wither gradually. This disease mainly affects the leaves of the plants instead of the fruit, so your cannabis flowers are safe from it. 

If left unattended, leaf septoria can ruin the entire foliage of cannabis plants. This will ultimately affect other foliage in your growing environment that will affect the overall health of the plants. Your harvest will be affected and the quality of your yield will surely decrease. 

Leaf septoria is specifically a prevalent disease that thrives in humid and wet conditions for an extended period. One of the best ways to beat this disease is by early detection that is essential for all types of gardens. 

How to Beat Leaf Septoria? 

Aside from early detection, there are valuable steps that you must follow to beat this dreaded plant disease. To learn all of it, check out our steps below: 

  • Cut the infected leaves immediately- The very first step to do in overcoming yellow spots on cannabis leaves or leaf septoria is to remove all of the infected leaves immediately after it showed initial signs of infection. If you can remove this early, it can prevent the spread of the infection. Once you’re done removing all the infected leaves, burn it right away. There are instances that the infection can reach the tip of the flowers which will force you to remove the foliage that will instantly weaken your plants that affect its overall health and quality. 
  • Provide better ventilation- Your growing environment, especially indoors must have good and improved air circulation. There must be proper air ventilation as well as circulation within your growing environment for the plants to breathe naturally and prevent any moisture and humidity from developing. By doing this, you can significantly reduce the risks of developing diseases, not just leaf septoria but also other pests and diseases. Just add a couple of fans that are strategically placed on your indoor growing environment. Also, make sure your plants are separated with the amount of space from each other. For an outdoor growing environment, try to prune and trim your plants to create better airflow. 
  • Prevent moisture from setting in- Since this is a type of fungus, leaf septoria thrives well on moist areas that are why you must avoid any moisture in your growing environment, especially indoors. Stop watering your plant’s overhead as this will make the leaves wet. It will make your plants susceptible to develop fungus such as leaf septoria. When watering, just do it slightly less so that the soil and the plants can absorb it very well until it dries out completely. Make sure you water your plants during day time. 
  • Apply a thick layer of mulch- During winter; your plants are susceptible to develop diseases such as leaf septoria. The fungus can easily spread because of moist and low temperatures. Since you cannot replace your growing medium during winter which is also the germination period of your plants, you must apply mulch. Before you apply a thick layer of mulch, make sure you got rid of any decaying foliage to prevent any fungus from developing. Next, dry the soil out and proceed in applying the mulch on top of your growing medium (soil in particular). Mulch helps in maintaining the moisture and temperature of the soil to provide protection to your plants and prevents fungus from developing. 
  • Get rid of weeds- For outdoor growers, weeds won’t just compete with your plants with the soil’s nutrition; it is also a perfect host for fungus to develop. With that in mind, you must get rid of weeds immediately. Uprooting weeds is a lot better than mowing or cutting it.
  • Use fungicides- Luckily, leaf septoria can be treated using fungicides to prevent further spread of the fungus. You can apply it easily to your plants through controlled spraying. There are mild to heavy-duty fungicides that you can choose from in the market depending on the severity of the infection. 

Last Words

Preventing leaf septoria or the yellow spots on cannabis leaves are not as daunting as you might think of it since the methods and resources used are highly available. Instead of waiting for leaf septoria to happen on your cannabis plants, you must prevent an infection from happening. By following the methods we provided above, we are pretty sure that your cannabis plants are safe and sound from this dreaded disease. 

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