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Compost vs soil improver

Chris234Chris234 Posts: 1
in The potting shed
What's the difference between compost and soil improver? I see books, articles, garden centres and websites discussing how to use either/both in the garden, but it's not clear to me what the difference between the 2 is...except the price!  I want to improve my garden soil by adding organic matter, but don't want to spend more on a 'soil improver' when a cheaper 'compost' will do, and may even be the same.

Posts

  • NollieNollie Girona, Catalunya, Northen Spain.Posts: 6,155
    Its an interesting question and I agree there is a good amount of confusion as the terms can be used by manufacturers interchangeably. Any compost will beef up the organic matter in your soil and thus ‘improve’ it. Many things are soil improvers - compost, seaweed, comfrey, animal manure, green manure...

    I think of compost as a bulking medium with limited nutrient content. Good for improving soil texture, growing annual vegetable and flower seeds in and using as a mulch. A soil improver (or conditioner) is usually something you mix with your soil to enrich or rebalance it’s nutrient content, but it would be too strong to use to grow most things in undiluted. It normally states how much to dig in per metre.

    At least, that’s my interpretation and it might be wrong! I think the only thing you can do is read the labels, study the nutrient composition and decide if whatever the product is, its worth the cost.
  • DovefromaboveDovefromabove Central Norfolk UKPosts: 80,553
    MPC type potting compost breaks down and becomes powdery before very long. IME it does very little to improve the structure of the garden soil ... it’s certainly nothing like as good as well-made garden compost. 

    I buy bags of proprietory soil conditioner from Notcutts and use this to mulch my beds when we run out of our own compost from our compost heap.

    I think the bought stuff is mainly composted bark and that sort of stuff and it certainly improves our somewhat freedraining sandy loam.

    I think it’s worth paying a bit more for it. 
    “I am not lost, for I know where I am. But however, where I am may be lost.” Winnie the Pooh







  • PosyPosy Isle of Wight.Posts: 3,564
    I'm very much in favour of well rotted stable or farm manure if you can get it.
  • DovefromaboveDovefromabove Central Norfolk UKPosts: 80,553
    Posy said:
    I'm very much in favour of well rotted stable or farm manure if you can get it.
    Yes I use that on the veg patch
    but I tend to use the soil conditioner as a mulch on flower beds in case it’s a bit ‘under cooked’ and burns new growth etc ... perhaps I’m being over cautious but it works for me 😊 
    “I am not lost, for I know where I am. But however, where I am may be lost.” Winnie the Pooh







  • NollieNollie Girona, Catalunya, Northen Spain.Posts: 6,155
    Any compost, including MPC, improves my rubbish soil, Dove! However, not the best for that job, I agree.

    I use a thick layer of ericaceous compost of mainly bark origin for mulch, because my soil is so alkaline. Before planting, I worked in a mix of ericaceous compost, manure and grit. All this has ‘improved’ my soil noticeably, both in texture and a slight lowering of PH. But I would never add mushroom compost to my already alkaline soil. So that’s another thing to consider when making your choice... your soil PH. 
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