What's a good slow release granular fertilizer for Centipede yards and Bermuda yards in the South Carolina area? I'm looking for a powerful(green healthy) result, but not too risky to where it will easily burn. Does the weed and feed stuff work? I had a customer use Scotts Weed/Feed once and she ended up with more weeds, but healthier looking grass also. I had to put post emergent on it later.