Terrestrial Orchids and Ammonium Sulfate

[RJSquirrel]

Anyone use/used Ammonium Sulfate or Copperas Iron Sulfate in the soil around your terrestrial orchids? I think I need some sulfur and iron in my mix.. I dont know why other than the plants have started to talk to me .

I would like to add that this is not the perfect time of year to be applying liquid heat like these items to your soil. For container grown cyms/phaius/spathoglottis, I really feel like you can treat the terrestrial mix with these in small container sized dosed quantities that wont burn your plant or sterilize the soil in the mix. Ive read that 1 tsp of ammonium sulfate applied to the surface and watered in or mix the ammonium sulfate with your water and use it that way just steer clear of getting the mix on your foliage. any chimes ringing ? bells going off? Please don't do as I do, I don't want to kill your plants too

[Ray]

I would recommend against any copper compound near orchids, as some of them - particularly those with thin leaves - seem to be susceptible to copper-related damage.

As for sulfur, how about Epsom Salts? It won't effect the pH like the ammonium sulfate, and the Mg can't be bad.

[purpleplantman]

Sounds dodgy; application of superphosphate & ammonium sulphate have resulted in the death of terrestrials through agricultural zones of Australia, generally by screwing soil microbes & associated orchid symbionts.