| Peter's is one of the favorite fertilizers for commercial orchid growers in Florida (probably because it is readily available in 50# bags and priced for commercial use.
I use it and have had excellent orchid growth after all this is my business. I have never seen a problem from the urea base.
I do not recommend 30-10-10 fertilizers. The high nitrogen encourages leaf growth at the expense of flowers. Mediums (commercial mixes use much more peat moss than hobbyists) break down using the nitrogen to decompose. 30-10-10 is for these conditions or very old bark. If you re-pot every couple of years or grow in mediums other than bark and peat, I recommend a balanced 20-20-20 mix at a teaspoon per gallon.
I do not like high phosphorus fertilizer like 8-35-12, usually sold as 'bloom boost'. They do not seem to do anything special. A healthy plant blooms well. That said there is an exception to everything.
Nobile Dendrobiums should not get any nitrogen fertilizer after September or it prevents flowering. Yet Yamamoto Dendrobiums told me to fertilize the blooming size plants I am getting this week three more times with high phosphorus fertilizer as they are not fully developed canes yet. It is unrealistic for a hobbyist to have the experience to make this call.
My previously bloomed Nobiles are getting no fertilizer anymore.
Hence this is the basis for my recommendation of a balanced fertilizer once a week (more outdoors in rainy season less when not growing actively) at a teaspoon per gallon.
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jerry  |