The recommended dilution rates on fertilizer labels assume optimum or close to optimum growing conditions and usually assume monthly application. If you apply it weekly (4 times per month), then you should dilute to one-quarter strength.
If your growing conditions are less than ideal, usually meaning less than ideal light, then the plants will grow more slowly and use correspondingly fewer nutrients. Thus, plants that are growing very slowly or are dormant or semi-dormant should not be fertilized at all.
