When is a proper time to apply fertilizer to the yard? What would you recommend for our grounds, without serious evaluation?

"Since we are in a warmer climate, I would recommend applying fertilizer in the late spring just before the major growth season hits. At first glance one recommendation that I would make would be to add more variation in colour when it comes to the flower beds. I also noticed a bit of broadleaf starting just east of the water feature. That is something I would take care of immediately."