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Most orchids are grown in a mix that's primarily composed of bark chips. Sometimes bark chips are also a component in soil mixes for other plants.

As I was stacking firewood, I realized I happen to have a fairly large supply of bark. It tends to be from temperate forest trees - sometimes from pines, sometimes from hardwoods. It breaks off fresh firewood all the time. It's not rotten, since the trees have been recently felled.

Is there anything wrong with breaking up this bark, baking it to kill pathogens, and growing orchids in it? Any potential hazards to making my own bark chips?

  • I think you should go ahead and make your own, the only reason against doing this would be risk of contamination outside of a controlled environment. – Viv Mar 15 '16 at 0:40
  • Tree bark contains anti-fungal compounds (ever notice that fungi aren't growing on live tree trunks?). These dissipate after a year or more of the tree's death. – Jim Young Mar 15 '16 at 5:35
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Tree barks historically are used to grow orchids as that simulates their natural habitat where as epiphytes they cling to the branches as an air plant. In NZ pine bark is used, heat treated to 400 deg to sterilise it, and it may last 5 years without rotting which could damage your orchid roots. As they decay there may be some nutrient released to the roots, but this is offset by the need to use a higher concentration of nitrogen in the fertiliser. You might be better off to save yourself all these potential issues and use an inert media such as expanded clay pellets which are inexpensive, have a suitable wetting capacity, and can be resterilised for reuse.

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  • Thanks Graham! Would I be correct in paraphrasing your answer thus: 1) you can make your own, but make sure to sterilize it 2) but it might make more sense to use inert media – John Walthour Mar 16 '16 at 14:49
  • More like is it worth the trouble and risk to the health of your orchids to do this when better media is so cheap. – Graham Chiu Mar 16 '16 at 17:57
  • That is indeed a reason not to make your own – John Walthour Mar 16 '16 at 19:20

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