My basil has a weird problem that seems to be spreading on the leaves. It's basically white spots that are thinner surrounded by black spots.

I tried to find information online but couldn't find this.

Thanks for the help!

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  • I would suggest that you amputate.
    – Rob
    Dec 11, 2018 at 21:18

2 Answers 2


This looks like an insect that eats the material between the walls of the leaves: a leaf miner. You can see the translucent areas where the leaves have been eaten and the black spots are "frass" or excreta from the adults.

Seeing as this is a plant that you want to be able to consume the leaves of this makes applying any pest control difficult. As it is an annual I agree that throwing the plant out is the most effective method of control.

You should also check your other plants in case they might have issues as well.

I suspect this is thrip as the damage looks similar to here. If I'm right you should be able to use a magnifying glass and see the adults or larvae on the undersides of the leaves. The adults fly and can spread to many other plants.

  • Thank you! I will try to amputate more and see if it stops. Do they go away when I replant the basil after a while?
    – euge9522
    Dec 12, 2018 at 9:18
  • @euge9522 If they are on other plants they will spread back. Thrip are very hard to get rid of
    – kevinskio
    Dec 12, 2018 at 11:22

It looks like Thrips. I have them on my basil, but some of the basil is fighting them off with the plant's immune system. I have spots like that and then I have leaves with a dead Thrip under the leaf.

I got my basil from Johnnyseed.com They are the Prospera trademark type of the Genovese sweet basil. They are resistant to Fusarium wilt and downy mildew, but it seems they are fighting much more. I grew some this year and the deer stay away from it. I have a mole boring large cavities under everything but the basil. I used round-up year round on one end of the garden and everything is dying from diseases spread from the round-up to kill everything. I will need to use copper sulfate, and bleach to treat the garden to get rid of the ground born diseases, before I can use it next year but the basil is still growing strong, and it is getting close to 6 feet tall, and some leaves are 4 inches long, and mid summer there was some at 5 inches long. I am sure the seeds could be better as plants for next year. I have a picture I just put up with the dead bugs under my leaves. thripshedskin

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