Leaf Septoria on marijuana plants

Yellow leaf spot, also known as leaf septoria, are caused by Septoria cannabis and S. neocannabina.

These are fungal pathogens aimed specifically at marijuana plants.

It is brought about by warm weather and rain and effect marijuana grown outdoors.

It may also show up in nitrogen- deficient plants. Read this article and learn how to identify and treat yellow leaf spot.

Signs of leaf septoria

Yellow leaf spot initially shows up on the lower leaves of your plant.

These spots may vary in shade from white to a grayish brown to yellow, initially displaying little circular lesions.

Once it starts to grow it starts looking like a bump and its size continues to increase.

Signs of leaf septoria marijuana plant
Signs of leaf septoria cannabis plant

Yellow leaf spot will harm the leaves and often times the stems of the plant, although it won’t cause the crop to die off.

Want to make sure that you give your plants the best protection? I have created three various bottles to counter most diseases or pest in order to fight back!

Marijuana plant protector

Bergman’s Plant Protector

  • Protect your plants from diseases and harmful pests.
  • Consists of three 20 ml bottles
  • Enough plant protection system supplies for up to 20 plants
  • Suitable for soil, hydroponic and all other grow mediums

If for any reason this is not properly cared for it will lessen the marijuana plant’s yield.

The affected leaves will become dry where the spot is and overtime break and produce a hole at the point where the spot started off.

How to avoid and cure leaf septoria

The most affected leaves will become totally yellow, dry out and fall off.

You will want to get rid of the leaves that fell off or else you will end up with a landing turf for spores to overwinter.

Basically, they will hide out until the weather warms up and then that’s when they will wreak havoc.

Yellow leaf spot spores do their dirty work through traveling by water, wind and clinging on to things that pass by.

How to avoid and cure leaf septoria on marijuana plant
How to avoid and cure leaf septoria

You can avoid the damage yellow leaf spot causes your plants through crop rotation.

Basically, after every harvest you will pick a new location to plant.

If you are not able to do this, then after harvest, completely get rid of all leftovers from the last vegetation and till the soil really good to make sure all remains are gone.

Get the location ready using sterilized compost and mix it well into the soil.

Doing this will give the new crop plenty of nitrogen to provide a good, strong start.

If you don’t have any ready compost, you can mix in blood meal, fish meal or soybean meal to the dirt that is already there.

Therefore, you will be certain to have all the necessary nitrogen for your plant.

Make sure you proper disinfect any tools you used with rubbing alcohol or peroxide prior to putting them away.

Not sure if your plants suffer leaf septoria? Also read Symptom checker – Identify marijuana plant problems

Correct Nutrients

If you want to make sure that you give you plants the highest chance on getting the proper nutrients, or to prevent nutrient issues in in the first place, I have created a perfectly balanced fertilizer kit, ready to use for all marijuana plants!

Marijuana fertilizer set

Bergman’s fertilizer kit

  • Enough nutrients for at least 5 plants
  • All the nutrients from seedling to harvest
  • Usable for all marijuana plants
  • Suitable for soil, hydroponic and other growing mediums

One more thing you can try when beginning a new marijuana bed is adding a fungicide to the planting location prior to putting the seedlings and seeds there.

You have the option to buy one of the many natural solutions pre-made (at this link here) or you can make your own.

Applying helpful bacteria, like Bacillus Pumilis or a good fungi like Trichoderma will help the soil if you don’t have any compost to use.

Also, you may try spraying the site with essential oil combinations with cinnamon, coriander, neem, sesame or clove.

Fine misting the soil with compost tea or even baking soda will aid in avoiding yellow leaf spot spores from making a home at your site.

Download my free Grow Bible to learn how to grow strong and healthy plants!

Marijuana plant symptoms

  • White/grayish brown/yellow spots on leaves
  • Circular lesions on lower leaves
  • A small pimple-looking bump
  • Leaves dry and fall off
Leaf septoria symptoms marijuana plant
Leaf septoria symptoms cannabis plant

Remember to water your plants early morning or early evening time. Never water the leaves, only the soil.

By doing this, the sunlight will not burn the leaves.

Again, if your plants get infected by yellow leaf spot, it is important to always remove and completely destroy all affected leaves.

If you don’t do this, you will most likely regret it.

Affected leaves still contain the problem and can come back to haunt you because yellow leaf spot easily clings on to things and travels from one destination to the next.

Using the correct nutrients and plant protector will get you a long way and your plants will have less chance of getting sick, in addition of being less vulnerable for pests and diseases. I have created multiple grow sets which features all you need in order to grow healthy plants from seed to harvest!

Buy Gold Leaf marijuana strain grow kit

Buy your grow set

FAQ about leaf septoria

How do you treat septoria leaves on Cannabis plants?

You can avoid the damage yellow leaf spot causes your plants through crop rotation.

What causes septoria leaf spot?

Septoria leaf spot is caused by a fungus, Septoria lycopersici.

How does Septoria leaf spot spread?

Septoria Leaf Spot is a fungus and spreads by spores. As with other fungal disease, it establishes and spreads most rapidly in wet or humid weather


Have you ever grown marijuana plants that developed leaf septoria? Do you have other tips on treating or preventing it?

Please share your experience with us in the comments!

Happy growing!

Robert

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Robert Bergman

Founder

Robert Bergman is an Amsterdam-based marijuana grow expert who has years of experience from small grows to massive operations ... See profile