Depends on what fertilizer you are using. Find the product you like and then follow the directions on the package.

i dont have any fertilizer product. But im planing to use banana peel on my mini rose. But i dont know what is the perfect time.

Where you do live, please? We typically fertilize when the rose is actively growing, but in some places, that is all year. Banana peel isn't enough.

I don't know who started that "banana peel as a fertilizer" but it is an internet myth and has been debunked by the experts, throw it in your compost pile. Used coffee grounds provide more nutrients when mixed with the soil or in the compost pile, they also have a pH of 6.2 which is perfect for roses.

As for inorganic fertilizers: I use 1/3-1/2 strength Miracle Grow every two weeks. Whatever you use never use full strength and make sure to water well about one hour before applying, that way you won't burn the roots.

i live in Philippines. @diane_nj

and i dont know how to care for my mini roses.

I havnt try any fertilyzer but i water it everyday.

@cleangeek i will try to find that miracle grow and try. thanks guys.