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bought compost hot and smells of amonia

Hi We recently bought 3000L of steam sterilised spent mushroom compost from a supplier that advertises on this website.  The compost arrived on Monday (3 days late but thankfully here amidst all the chaos).  However when we started moving it to the vegetable patch we noticed that it was hot to touch and smelled strongly of ammonia. Is this normal?  We were planning to use it this year and I am concerned that it will not be good for our plants. 
Best regards


  • Pass your concerns back to the supplier. If there is a problem he should rectify it for you.
    A gardener's work is never at an end  - (John Evelyn 1620-1706)
  • Pete.8Pete.8 Posts: 9,983
    Mushroom compost is often mixed with chicken manure and can smell of ammonia when it's fresh.
    Alternatively if there's a lot of green waste in there, ammonia can form from the excess nitrogen.
    If it's hot it is still quite fresh.

    Either way it sounds like it's not rotted and shouldn't be used on your plants until it is as it will burn the roots.
    Once rotted down it should be fine, but as said above best to pass your concerns to the supplier.
    Knowledge is knowing that a tomato is a fruit.
    Wisdom is not putting it in a fruit salad.
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