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Round Brown Spots on Basil Leaves
By Mark Bingaman, eHow Contributor
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Basil grows best with a soil pH of 6.0 to 6.5.
A relative of mint, the basil plant (Ocimum basilicum) originated in India and today is a staple herb used in the seasoning of dishes across the world. Several forms of disease may be responsible when basil leaves begin to display a series of brown spots. Keeping the plant dry is key to avoiding most of them. Does this Spark an idea?
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⢠How to Care for Fresh Basil
⢠Leaves Are Turning Brown on Basil Plants
1. Bacterial Leaf Spot
o Bacterial leaf spot (Pseudomonas cichorii) produces round brown spots on basil leaves, with the plant first infected by splashing water during periods of wet, warm, humid weather. The spots are waterlogged and may produce a wet, rotting stem in the plant. The bacteria is carried in the basil seeds. The possibility of infection is reduced by avoiding overhead watering and keeping the surface of the plant as dry as possible. Providing ample space between plants also helps to keep the basil dry

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I've had some browning as well, but not exactly the spots as shown on the original post. This browning seems to come from the outside of the leaf in. I thought I might be overwatering, but after reading some articles I'm not so sure. I've posted a photo.
Any help would be appreciated. Thank you.

My basil is doing the same thing. I am totally clueless as to what it is. I love basil but don't know if it is safe to use when it looks like that.

Maybe you accidentally splashed fertilizer on the leaves? The new growth looks healthy so the plant looks like it will be ok.

Sorry to hijack your original post clearchannel.

So I reached out to my county extension office and this was their response. Hopefully this will do the trick.

"The basil would benefit from more light and air circulation. Gradually move it to full sun (it will cook if you do it too quickly, think your first day at the beach). It may be staying overly wet. Also do not wet foliage when watering. Make sure the cup is not blocking air movement."

OP, were you ever able to resolve this? I am having the exact same problem with my basil. Not sure how to treat it.

Hi I'm having the exact same black/grey expanding spots, how did you solve it?