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Will wood bark as a mulch cause nitrate deficiency?


Hello, this autumn I planning on planting a few trees(hazel-holly) and bushes(elder - all of them will be bare root), I want to apply a nice hearty mulch to these to protect them, I was planning on using cocoa shell nibs but they're way out of my budget!  The next thing I can use is wood bark, obviously cheaper, one worry I hold is that I've been repeatedly told that as this mulch breaks down it removes nitrate from the soil.   Will this cause nitrate deficiency? I only plan on mulching until they're established   Thanks


  • nutcutletnutcutlet Posts: 27,411

    I've heard that. Don't if it's true in practice as well as theory. You can always give it a food supplementimage

    In the sticks near Peterborough
  • Dave MorganDave Morgan Posts: 3,123

    Actually it's a myth. Recent scientific data has shown it has no significant effect on the nutrient levels in the soil. Bad soil management by adding chemicals and additives to the soil cause far more damage than bark which is a natural material and breaks down over time adding structure to the soil. I can't find the link for the recently published material, but it does have plenty of scientific evidence to back it up. I use bark in quite a few gardens I work in and based on a layman's point of view I see no significant difference in plant health than other gardens. 

  • PalustrisPalustris Posts: 4,297

    Agree. We have been putting shredded bark from our garden on the beds for 20 years and there is no sign of nitrogen loss.

  • Hostafan1Hostafan1 Posts: 34,854

    I've tried to find out as much as I can about this and I have to say I've found no conclusive evidence about nitrogen depletion. 


  • As a gardener of many years I've also known this to be so (after all, it makes sense to be so) having said that, I never found it making any noticeable difference in my garden. I have two rose beds which are mulched with bark chippings and the roses themselves are very healthy.

    I would just add that my source of supply is from my local Forestry Commission (I live on the edge of a pine forest) and find that due to the fact that my bark chippings contain pine needles, results in me having no problems with cat fouling.   

  • Chris MasonChris Mason Posts: 159

    Thank you all for your replies

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