| I don't know about the braking time of urea, but concerning the orchids need for fertilizer I learned some basic things:
You have to avoid the accumulation of salt (fertilizer) in the pot, on roots and potting medium by soaking in water and flushing well, regularly.
Orchids are relatively slow growing plants, as result they need less food then non-orchids and can survive for long time without fertilizer.
You can use any balanced fertilizer like (20-20 20) or something close to this, in a light dilution: about 1/2 or 1/4 of the usual.
Fertilizers labeled as "orchid food" have the same components, just the instructions demand a lower concentration. I use Shultz Orchid Food (19-31-17), it works well for me.
As I remember, a high % of N stimulates foliage growth.
Aniko. |