The Seed Fair

Are You 21 or Older?

It's part of our commitment to social responsibility to ensure visitors to the site are of legal age to use cannabis products.


Yellow Spots In Your Leaf and How Leaf Septoria Can Affect Your Growth

Yellow Spots In Your Leaf and How Leaf Septoria Can Affect Your Growth | The Seed Fair

Cannabis growers must know about diseases that can impact their plants and possibly demolish their plants. Marijuana plants are vulnerable to a wide range of diseases that can deal harm to plants. An exact example of such a disease is yellow spots in your leaf, otherwise called leaf septoria.

These fungal infections are the direct effect of Septoria Neocannabina and the S. Cannabis, these twin pathogens usually attack cannabis plants. Yellow spots in your leaf are most common in wet and warm weather. The focus of this attack is on cannabis plants that are grown outdoors, however, marijuana plants that suffer nitrogen decay can easily be affected by this disease. So then, what does leaf septoria entails, and how can it be treated?


What appearance does leaf septoria take?

Begin by examining the lower leaves of your plant to see if it has leaf septoria, what you should be looking for here are spots that resemble circular lesions. These spots can be yellow, white, or grayish. It can also take a shade of the above-mentioned colors, the colors are noticeable at the flowering phase. Immediately the problem takes root, the initial bump will spread across your leaf and get bigger as the disease continues to spread.

These yellow spots in your leaf will damage your plant’s leaves and can sometimes injure your stem as well. While the situation will not kill your crops, it will tell on your yield. When Leaf septoria happens, your leaves will become dry at the spot where you have your bump. With time the dry spot on the bump will wipe out, leaving you with a hole at the spot where the fungal pathogen first appeared. The buds of your cannabis flowers will not be affected, however, the harvest will be greatly reduced. An effective way to win over this attack is to detect the problem early and take active steps to fix it.


Indicators of leaf septoria in marijuana plants

Marijuana plants will show signs when they are under yellow leaf spot attacks, the spots often come with a darkened horizon, while the spots will often serve as a shelf of spores. If you see small bumps on the plants that look like pimples, it is a sign that your crops need attention. Also, dry falling leaves are another indicator of leaf septoria.


How to alleviate leaf septoria when you notice it

The leaves that suffer the most severe damage from leaf septoria, often turn yellow and dry out, followed by falling off the plant completely. Remove these leaves as soon as you can spot them, if allowed to survive the winter, they become a hub for spores. They will stay here until the weather becomes warm, when it eventually becomes warm they attack your crop and cause damage to it. These spores can travel by water and wind. Interestingly, whenever they pass anything, they cling to it until they attain a foothold.

The above steps work best for your plants only when your lower leaves are the victim of the attack, where the attack focuses on your flowers, leaving your foliage in its place. Where you remove the foliage from your flowering area, you will end up with a weakened plant and reduced buds. Therefore, maintaining sick leaves here is preferred over having little or no leaves left from your pruning exercise.


Prevention of yellow leaf spot


Begin by preparing your soil

A very effective option to go with here will be to rotate your crops after your harvest, this entails selecting a new location for each crop. This way your marijuana crops will be grown on pest-free soil that is both fresh and balanced for your crops to grow. If you cannot rotate, ensure you take out every leftover from your recent crops, once down, check the soil to satisfy yourself that you have nothing left. Doing all of this will keep leaf septoria at bay.

If you till your soil correctly, get a sterilized compost and blend it completely into your soil, this will give your new crops adequate nitrogen, and help them get off to a fantastic start. Where you cannot get sterilized compost use things such as soybean, blood, and fish meal to improve upon your soil before you plant afresh. This way, your bruce banner crops will have adequate nitrogen.


Take out weeds

Of the things that can prevent spores from making their way right from the ground to the top of your plant is Mulch. Begin by taking off dead foliage and clear your soil adequately. Your soil should be dry before you apply your thick layer of mulch, once you have this in place, go ahead to water your plants.

Give no room for weeds to grow around your marijuana plants. Similarly, your hose nettle and your nightshade are fantastic hosts for Septoria lycopersici. Stay active and take out weeds once you see them, this way there will be no place for fungus to hide.


Regulate your temperature, air, and moisture

You will need to regulate the moisture while you are growing cannabis, your marijuana plants are best watered early in the morning and evening. While watering, avoid watering the leaves and focus the efforts on the soil alone. This way sunlight won’t affect your leaves. Where you sight yellow leaf spots, ensure you remove the affected leaves to keep your plants in shape. Leaving affected leaves in the growth area will expose your plant to danger. Fungal pathogens on affected leaves are mobile and easily cling to things attached.

Indoor farmers will have to regulate their humidity level and temperature, as it plays a significant role in the success of their crops. Control these conditions and ensure you make the necessary changes needed to prevent issues in the future.

Similarly, ensure there is adequate air in your growing area. Get an additional fan if possible, and design your layout in such a way that it creates adequate space between the plants. For marijuana plants grown outdoor, they should be pruned, allowing for adequate airflow. The bushy area of your plants can be left alone, however, your leaves should not touch each other or lay on top of each one. This way, air will get to the plants, if you can, get an electric fan for outdoor farming.


Leaf septoria treatments

One way to stay yellow leaf spot-free is to put fungicide in your soil, before putting your seeds. Similarly, they are natural solutions to try and you can make one yourself as well, a fungicide and disease control spray is a good and effective start. Some farmers go with copper-based fungicide. Irrespective of your choice of product, observe the instructions listed on the product and prevent the spray from getting to the buds.

Similarly, you can add some beneficial fungi or bacteria to the soil, where compost is not convenient. The two best options to go with here are Trichoderma and Bacillus.

For other farmers, the use of relevant oils keeps leaf septoria at bay, and Neem Oil is a choice product among farmers, as it treats a wide range of land diseases and pests. Also, don’t forget that the oils have strong scents, a reason you should not apply them to your buds. This will help you prevent contaminating the aroma and flavor of your plant. Furthermore, Compost tea or banking soda can be added to the soil, as they are active in preventing yellow leaf spots and keeping spores away.


Distinguish between your seed providers

Be prudent with your choice of seed supplier, as seeds with powerful genetics are healthier and are safeguarded against diseases and pets invasion than others. For this purpose, obtain your seeds from a trusted seed bank. Also, where leaf septoria goes on, seek support from your supplier and ask for advice on the best plants to buy to avoid this hazard from repeating.


Maintain a clean environment

A clean environment is a crucial asset to growing marijuana, clean your farm space regularly, this way you can easily spot problems before they give rise to major issues along the way. For indoor farmers, this factor is most important. Your farm area should be kept clean at all times.

Similarly, a dominant mistake with growers is their failure to disinfect, as well as clean up their tools after taking care of a leaf septoria problem. Peroxide or alcohol should be used to clean and disinfect the leaves, removing pathogens along the line. Don’t overlook anything, ensure all your tools are properly cleaned. Sometimes the reason the problem returns is the unwillingness to clean your work tools.



While yellow leaf spots will not completely kill your marijuana plants, they can cause severe harm to them. You will also battle with low yields and poor growth. However, if you stay on your toes, you will notice this problem on time and stop additional harm. Prevention on the other hand remains the best option for preventing leaf septoria, and other plant-related diseases that are noticed on crops.

If you still have the same issues after following through with your recommendation, the problem might be with your plant strain. Plants genetics play an essential role in how your plant survives diseases and pest attacks. Research adequately before you buy your strains, this way you will rescue the time and resources to be spent later on. We have your bank when it comes to giving you seeds that stand the test of time.

Leave a Reply