I am a bbq lover and all the times I find myself throwing ash , I was googling on 'How to recycle bbq ash and found it can be a killer for weed. on the website it says

BBQ ash can be repurposed as a fertiliser or weed suppressant, by simply adding it to soil. This adds potassium carbonate, which is a helpful nutrient to many plants. Ash can stop weeds growing by increasing the pH level of the soil.

If this is true what is quoted above and how should I use the ash as it might fly and be more harmful as I m trying to grow grass as well.

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    I think it would depend on what sort of BBQ you are using - gas, wood, charcoal, briquettes Jul 9, 2023 at 12:02
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    Sounds like another internet myth to me, in the same league as using salt or vinegar as weedkillers. Lots of things will kill weeds but the danger is that they will poison the soil as well. You'd be better off with a proprietary weedkiller.
    – Peter4075
    Jul 9, 2023 at 12:42
  • Lawns crave nitrogen for greens, not potassium for roots. Wood ash may be one thing from a fireplace, but BBQ ash can contain carcinogenic drippings. Maybe use sparingly in compost and let nature take its course. Jul 9, 2023 at 16:22
  • Are you using briquettes (compressed coal dust) or actual charcoal (so wood ash?)
    – Ecnerwal
    Jul 9, 2023 at 17:05
  • @Ecnerwal it’s charcoal
    – localhost
    Jul 9, 2023 at 22:24

1 Answer 1


The ash has no idea what's a weed, so if you dump on enough to kill weeds it will kill plants you want.

IIRC coal ash (from allegedly charcoal briquettes, almost entirely coal, actually) is considerably more toxic than wood ash (actual charcoal from wood), in general.

  • So it is not good. How do I wash it away coz I might have spreader in the garden as I m waiting for my garden to grow green
    – localhost
    Jul 9, 2023 at 22:25
  • Wood ash (in moderate quantities) as contained form actual charcoal can be good. spread it around more if you dumped a lot in any one location where you're trying to grow anything.
    – Ecnerwal
    Jul 9, 2023 at 22:30
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    @localhost To give a sense of scale, if you spread the wood ash over 1,000 square feet, the University of New Hampshire recommends no more than 20lbs. per year for garden/agricultural land, and 10-15lbs. per year for lawns. extension.unh.edu/sites/default/files/migrated_unmanaged_files/…
    – MackM
    Jul 10, 2023 at 13:47

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