For a complete answer, it would help to know:

• What kind of plant?
• What environment is it kept in?
• You say newly-developing- is this a new plant that will be a bonsai or one that is further along in training?

You can see why bonsai is not the hobby for everyone-it deals with so many variables.

Plants make their own “food” using sunlight. The ingredients in fertilizer help supports the plant's life processes. A plant in bright sunlight in full active growth will use much more fertilizer than a dormant plant.