What is the difference between liquid and granular fertilizer formulas?

Liquid applications are easier to burn with and generally not recommended, as it will be 100% synthetic.

With granular applications you have your choice of going for all slow release and non-burning, or a mixture of fast and slow release. The slower release in the fertilizer formulation, the harder it will be to burn with.

You should NEVER fertilize a dormant, brown lawn, and generally you do not fertilize in high temperatures. On our JRK 4 step program for instance, July is always skipped for this reason.