Tuesday, 20 October 2015

Cloves as an anti-fungal

Big Brassica plants like Brussels Sprouts and Purple Sprouting Broccoli are very susceptible to fungal growths, which seem to thrive in the cooler damper conditions of Autumn. Inspecting my sprouts at the weekend, I saw this:

And this:

It's a type of Sooty Mould, which is a fungus that often grows on the "honeydew" (excretions) of sap-sucking insects such as the Whitefly - a common pest of brassicas. The fungus in itself is not particularly harmful (though it can reduce plant vigour by inhibiting photosynthesis), but it's definitely unpleasant and unsightly.

The leaves and stems of my Brussels Sprouts are mottled with little patches of the fungus.

Even some of the sprouts themselves are affected.

The fungus will only affect the outer leaves of the sprouts, which will be removed before cooking anyway, so this is not a major issue, but I would like to stop the problem getting any worse.

It is alleged that in the case of a mild infestation you can wash Sooty Mould off your plants with water (preferably warm), but I decided to use a remedy I had seen mentioned on Twitter the other day - an infusion of Cloves, which apparently have powerful anti-fungal properties. With little information to go on, I had no option but to experiment. I put about 30 Cloves in a saucepan of water and boiled them for about 5 minutes.

Following a suggestion from Jane (who was initially baffled by the fact that I was boiling Cloves), I added about half a teaspoon of ground Cloves from a jar in the spice rack. This made the concoction a much darker colour.

Later, when the water had cooled I poured it into a spray bottle and gave the Brussels Sprouts a thorough soaking, trying hard to ensure that every surface of every leaf was covered. I don't know whether this remedy will work at all, and if it does how soon I should be looking for results, but even if it doesn't work I can't imagine it will have done any harm - just as long as the sprouts don't end up tasting of Cloves!!

Funnily enough, this year there seem to be far fewer Whitefly around than normal. Certainly not a serious infestation like last year. Last year I tried spraying my Sprouts with a Garlic infusion to kill the Whitefly. I'm not convinced it did much good, so my hopes for the Clove spray are not high.


  1. Do post the results of your clove experiment, as I have to deal with this issue on a regular basis! Thanks.

  2. I hope it works for you, we have to do what we can to combat these problems.

  3. Horticultural soap solution (rather than diluted washing up liquid, which contains a lot of non-plant friendly additives these days) is also useful against this fungus. Extract of cloves is available in small bottles from Asian grocers (& possibly chemists as it used to be a toothache remedy) and might be easier to use.

  4. I will be keeping an eye out for the post with the results.

  5. It will be interesting to see what happens. Many of these remedies are not very effective, but every once in a while you do come across a winner, so I think they are always worth a try.

  6. I hope it works. I wonder if it would work on black spot on roses.

  7. It will be an interesting experiment no matter the outcome.

  8. Hi Mark, im glad to see you decided to give my clove suggestion a go. Best of luck

    1. Hi Daniel; Thanks for the suggestion. I have now read on your website about your method of preparing the Clove solution and I see I got it wrong (I boiled the Cloves, which may have destroyed some of the Eugenol), so I may have another go.


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