I appear to have a black sooty film on my bay tree on about 30 per cent of the leaves, can anyone tell me what this is, how to get rid of it, and what causes it, thanks


  • Dave MorganDave Morgan Posts: 3,122

    A light spray with diluted washing up liquid will help.

  • philippa smith2philippa smith2 Posts: 6,168

    I've noticed this more on Bays which are congested and don't have a good air circulation. 

    I think Edd is correct in that it is more unsightly than harmful and providing you wash the leaves thoroughly, you can still use them - either fresh or dried - for culinary purposes.

  • WelshonionWelshonion Posts: 3,115

    Frankly with all the rain we've had the sooty mould would have washed off if it was going to.

    The introduction of insects is impractical for most gardeners. They are either there or not and probably not at this time of year.

    If you really want to get rid of it - it will harm the bay - you will have to take more drastic action.  But if the bush is small and the weather sunny, you can sit down and wipe off the critters on the undersides of the leaves with warm water and washing up liquid.

    It all depends on whether you are a chemical-user or not.

  • philippa smith2philippa smith2 Posts: 6,168

    The sooty mould won't just wash off........however much rain - if it is caused by aphids, it is too sticky.

    I agree about the intro of insects....impractical in most cases.

    Depends on the size of the tree........a big tree will deal with it........if a small tree, cleaning the leaves will help but unless you are able to deal with the problem at source, you will just have to keep doing it.

  • Pete8Pete8 Posts: 2,907

    Don't know about yours, but my bay grows at a scary rate once it gets going in the spring. 
    I cut a couple of 12' bays back severely last spring. They soon shot back up, so maybe try some hard pruning and a mulch.

    If the underside of the leaves have small brown bumps on them (often with a little bit of white 'fluff' at the base) then it's likely scale insects.
    When I get an attack of such things  - I'll whisper the next bit -  I go buy some spray from B&Q - food safe if you intend using for cooking. I do use it responsibly of course.
    Good luck

  • WelshonionWelshonion Posts: 3,115
    Edd wrote (see)


    Learn to cook and pick them off as fast as you can and use them.

    (What does this mean?)

    The only other way, I have found is flyspray in cans. Please do not be lazy and use chemicals.

    Flyspray in cans ??  A chemical, surely? 




  • philippa smith2philippa smith2 Posts: 6,168

    Edd...........Sorry............I didn't put that as well as I could have done . I agree wholeheartedly..........I've used diluted washing up liquid to clean leaves of various plants as well as soft soap. Keeping as natural a balance in the garden is the way to go rather than immediately zapping with chemicals. 

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