White Powder

I know this is a strange query and I understand a difficult one to answer but I am just looking for suggestions and/ideas to help me decide what to do. 

Last week I emptied and cleaned the greenhouse and found a bag of white powder in there next to a bag of vermiculite (only moved in in April and was a lot of stuff left behind). Now I am wondering what it might be.

It is a sealed 3kg clear bag of whitish powder, looks a bit like sand and feels (through the bag) a bit gritty, fine grit though. It is obviously new but the label has been washed off, tiny bit of red and yellow left of it and the word 'three' is all that can be read of it. 

I know the previous owners were very keen gardeners and grew a lot of their own plants from seeds.

The soil here is acid and I wondered if it might be a bag of lime but then I thought 3kg is very small.

Any ideas gratefully received or should I just throw it away? 

Gardeners, I think, dream bigger dreams than emperors. – Mary Cantwell


  • NewBoy2NewBoy2 Posts: 1,307

    Take it to your local Garden Centre and ask the oldest person there


    Never change Tigers in Mid Stream
  • fidgetbonesfidgetbones Posts: 13,900

    Could be calcified seaweed. could be lime, could be rock dust.

    If you don't know what it is, I would err on the safe side and bin it.

    You don't stop doing new things because you get old, you get old because you stop doing new things. <3
  • DD...........have you tried sniffing it thru a rolled up fiver ?image

    Could it be Bonemeal ?  Or Blood, Fish and Bone ?  Does it smell at all ? . These 2 are the sort of thing which keen gardeners would perhaps have to hand altho the g/h wouldn't be the best place to store itimage 

  • pansyfacepansyface PEAK DISTRICT DerbyshirePosts: 16,175

    Ask the previous owners?image

    We moved into a house once and found a stash of Polish pure alcohol hidden in the shed.image Didn't ask his wife if he wanted it back.

    Apophthegm -  a big word for a small thought.
  • Pansyface.............sounds worthy of a new thread....." What extras did YOU get with your new house ? "   imageimage

  • Thanks for great responses; Newboy, we live in France & not sure my language skills are quite up to explaining this problem without possibly getting myself arrested. image

    Phillipa I did sniff it (not through rolled up £5 note or Euro for that matter, but it doesn't smell of anything. image

    Previous owners have left the country and we no longer have contact details unfortunately. 

    Is there some kind of lime test I could do - will it turn blue of anything fancy if I put something on it?? image

    Also, I know this might sound stupid, I have no idea what it is but I have heard of perlite, is that a white powder, it was next to the vermiculite??

    I do hate waste, but think this one is for the bin. image

    Gardeners, I think, dream bigger dreams than emperors. – Mary Cantwell
  • DD..........Perlite is fairly obvious......looks and feels like tiny balls of polystyrene ( for want of a better description ).  It isn't a powder and wouldn't degrade into powder form with age.

    If you aren't sure and can't find out, take it to the recycling centre........if it was anything like ours , they will soon put you right.  You don't need to be fluent to look helpless and say you don't know what it is image


  • DorsetUKDorsetUK Posts: 441

    'Two inorganic soil additives common in horticulture are perlite and vermiculite. Both are made by expanding mineral materials mined from nature, but their properties and uses differ. Perlite is white and porous, with sharp edges. Vermiculite is brownish, softer, and somewhat shiny. Both help aerate and lighten soil mixes and are valuable in container plant culture and mixes for rooting and seed starting.'

    above is from the web so your bagful doesn't sound like Perlite.  Not salt by any chance? ie rock salt rather than domestic.

  • pansyfacepansyface PEAK DISTRICT DerbyshirePosts: 16,175

    I found it in the greenhouse. Honest, yer honour.

    Apophthegm -  a big word for a small thought.
  • My point exactly Pansyface - image

    Is not salt, obviously not perlite.

    Might keep it until my Open Garden Day and have is part of the entertainment. image

    Thank you all. 

    Gardeners, I think, dream bigger dreams than emperors. – Mary Cantwell
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