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bhammie85

Sudden Brown Patches on Basil and Mint

bhammie85
9 years ago

Hi all,

I have noticed a sudden proliferation of brown spots on my basil and chocolate mint plants and it has appeared in the last 2 days. I've attached some photos; any ideas of what to do?

Other info:
- plants are outside, lots of sun.
- haven't fertilized recently
-doesn't look like fungus/fuzzy
- only water when they start wilting
- have had a decent amount of rain lately (in St. Pete) but they don't sit in saucers so shouldn't be waterlogged
- have been battling against white flies and leaf miners for a couple months but this is the first time I've seen this happen
- I've been gardening for a year so I have a little familiarity with other things that would kill them (tomato leaf curl virus, mites, terrible FL soil, etc) but I'm guessing this is another virus or bacterial infection

This is affecting 3 kinds of basil and the chocolate mint, but not my sweet mint or rosemary (yet). My chard has also been looking weird lately so I have a photo of that as well.

Thanks for any help!

Here is a link that might be useful: Dropbox link to photos

Comments (11)

  • User
    9 years ago

    I've seen this before on my basil, but not to this extent. Basil is so easy to grow, I'd almost say to throw the plant away and start over. I have accidentally planted a healthy basil plant at least once. But I am a novice gardener so I defer to others in the forum.

  • carolb_w_fl_coastal_9b
    9 years ago

    If it were not summer time, I say that looked like frostbite. Perhaps something caustic spilled, sprayed or other wise got on those leaves?

    Hmm - quick image search for 'diseases of basil leaves' suggests it may be a mildewâ¦.

    This post was edited by carolb_w_fl on Tue, Jul 29, 14 at 10:21

  • chinchette
    9 years ago

    I have the same thing. Already have tossed it and started over and got the same thing.

  • coorscat
    9 years ago

    I am down in south Florida and I get this almost every year during the rainy season. It is some form of blight. If the leaf is really bad, I remove and wrap in plastic and throw away. If it is just a spot, I pick the leaf, pick off the spot and then use the leaf in the kitchen.

  • bhammie85
    Original Author
    9 years ago

    Thanks everybody for the feedback.

    carolb_w_fl I saw that mildew photo and my leaves aren't fuzzy, just dying on those brown spotted areas. I also haven't been spraying anything - and no changes to the soil or how I water them.

    coorscat, I was thinking it might be something like that. It's affecting most of my plant (the genovese one, though not as bad on the other basil types) so if I pick off the bad leaves I'll lose all the leaves. I may try to cut it all the way back to see if it will make a comeback though.

    I did a little more research and it looks like it might but fusarium wilt or late blight, both of which are a bummer.

    Anyway, if anybody has any more ideas of how to treat it/avoid it, I'll take suggestions!

  • chinchette
    9 years ago

    Did you have any lucK?

  • bhammie85
    Original Author
    9 years ago

    Chinchette, whatever it was eventually stopped after a week or so. The plants look pretty scraggly now but I cut them back so hopefully that will spur some new growth. They look a little stressed (the leaves are a little curled), but that's to be expected. So I suppose in this case my only advice would be to wait it out.

    Thanks!

  • chinchette
    9 years ago

    Mine are pretty much dead. Ty basil does okay for me.

  • Caileigh Richmond
    7 years ago

    My basil plant had this. I took it inside, planted it in an old milk container that had a little tiny bit of milk residue in it, watered it well, and left it in a spot with moderate sun. I also plucked off any leaves that had the spots and threw them away. My plant is smaller than before but it has no more brown on it and it seems to be recovering from the spots and the harsh haircut it had. I don't know what it was, but I figured the calcium and nutrients from the residue in the carton would feed the soil, and it worked like magic!

  • wisconsitom
    7 years ago

    Could be downy mildew, not the more commonly known powdery mildew. Downy mildew can be quite serious on basil.

  • sharon's florida
    7 years ago

    I would also love to know what that is as I've seen it on every sweet basil I've tried to grow. I have been in Florida my entire life and have never been able to grow basil. I can grow African blue basil and Thai basil, but not sweet basil. Everyone says it's so easy to grow, but not for me. Can't wait to hear more responses.

    I did a google image search for downy mildew and it certainly could be that. The under side of the leaves look similar to mites, but the top spots are brown splotches.

    So how do you deal with downy mildew on basil?