It sure would help if you could tell us what 'part of the country' you are in, please? I buy my orchid fertilizer from Amazon, so if you have access to them, you can get most types.
But it depends where you are and what your water is like, (pH and soluble solids) to determine what kind of fert you should use.
Also important is what kind of orchids your wife has, and where she is growing them. (indoors, outdoors, in a greenhouse?)
