I have a basil plant growing and I have noticed on a few of the leaves -- only on this one type of basil plant -- I am getting these faded black spots. I tried looking online to see if I could find anything that looked like the spot but the closes thing I could find was "Cercospora Arachidicola" but that looks a little darker than the one I have.

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Any ideas?


This is most likely to be a fungal disease. Prevention and treatment measures include:

  • keep plants well aerated by trimming regularly and giving them plenty of sun is a must
  • Watering in the morning and at the base of the plants rather than evening also keeps moisture levels down in cooler temperatures.
  • Natural controls include fungal soap, a baking soda and water mixture, etc. - Trim the affected leaves and treat the rest of the plant is probably your best measure
  • That you for the information but I was looking for more details on the issue. A name more than anything. If figured it was fungal but it has happened before and I want to try to prevent the problem by finding out what in the area would be causing it. – Nicholas Sep 22 '12 at 0:29
  • 1
    Nicholas, fungal spores are around us all the time, like bacteria. Damp weather or conditions increases the number, but whether a plant succumbs to infection or not is down to the plant's health and susceptibilities and its growing conditions. Fungal leaf spots of this sort are spread by water splash, so ensure you only water the compost and keep the leaves dry. – Bamboo Sep 22 '12 at 16:18

I believe I have the same problem. I am at a loss for the name, but these black spots can be caused by small wormy creatures that live inside of the leaves. They're easy enough to check for, just pull off a leaf with a spot on it and tear a line that is more or less tangent to the spotted area, and try to open the leaf like an envelope. There should be one or two tiny caterpillar-looking punks trying to escape their freshly excavated home. I know that these bugs exist, but short of tearing every leaf off my basil plant, I've no idea what to do about them.

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