Copper and your orchids

[camille1585]

In France, we have a well known organic fungicide called 'bouillie bordelaise' It's a mix of copper sulfate and lime. It works best in prevention of fungi related problems, and can cure infected plants to a certain degree. The only drawback is that it turns eveything blue, unless you get the colorless kind! Just as a word of warning, it should not be used at temps over 24-25°C (75°F) as it becomes toxic to the plant, causing burns.

I would not use it at every watering, because if the medium behaves in any way like soil, the copper will build up in the medium and high doses kill plants. Also, I know that in the case of vineyards, they don't spray while the vines bloom as it causes the flowers to abort.

Personnaly, for all the above reasons, i woul not use it on my orchids, unless I really needed it.