Let us speak about Physan

[Intruder]

The Physan is not more available in Belgium but well in Germany. Having required near a German orchids producer if he could provide me some he answered me that he never used Physan because these slowed down the growth of the orchids. He has refers to an article published in the AOS review Orchids a few years ago. Have you see this article and what do you think about this assertion?
Many thanks for your comments.

[Rhonda_in_FL]

I have never heard of that concern here in Florida. We use it all the time. I think anything in excess will stunt growth or deform flowers.

Personally, I don't use it on plants. I prefer a systemic product. I use it to clean my growing area.

[Ray]

I use it on my entire greenhouse on a periodic basis - glazing, benches, plants and all.

Some plants don't like it - particularly ferns - but the only orchids I have seen negative effects with are the leafless ones.

It is important not to overdo the mixing rate. I stick to no more than 1 teaspoon per gallon (a bit over 1 ml/liter), or you will have issues.