| I believe the problem with urea-based fertilizers is that below a certain temperature, plants can not absorb the urea-based nitrogen. Therefore urea-based fertilizers don't work well with cooler growing plants. I have heard, quite a few times, not to use urea-based fertilizer on Cymbidiums as they will not absorb it in the cooler months and the fertilizer will build up and do all the nasty things it does when it builds up too much. |