Copper and your orchids

[Ray]

Copper is a great fungicide, but also a great herbicide - especially in thin-leaved plants.

That's why I recommend Physan or even a cinnamon extract over it.

[Undergrounder]

you mention thin leaved plants, have you heard of its use as a minor adjustment to the watering regime, ie: only on the roots? I was imagining adding a slightly larger amount that is usual on fertilisers as a type of systemic, ie: the copper build up is taken up by the roots and adds to the plant's general resistence, as well as having a mild antifungal effect on the surface of the roots themselves.

P.S. I realise it's probably a matter of 'try it and see', and a few posts have good reasons for not doing it, or at least keeping a slightly basic pH in the fertiliser to stop it being herbicidal.. but it sounds like a powerful fungacide, so it might be worth it as a small experiment on my part.