QuestionI have a 5000 sq ft Floratam lawn in deep south TEXAS and have been having problems with some dark color spots on some areas. Also, not all sections of the lawn are equally in thickness and they were all planted at the same time. Finally, how often and for how long its recommended to water this time of grass.
Answer I cannot picture in my mind, "some dark color spots on some areas." You need to be a bit more specific. On those thin sections, apply some top soil or similar organic product. "Milorganite" is an organic fertilizer which should cause improvement. Your objective is to encourage rooting on those grass runners.
I can offer only general guidelines regarding irrigation.
Recommendations for frequency and quantity are based upon prevailing weather conditions and measurements done over a period of time. The Extension service for your county will have the current information.
Obey the regulations that are in force for your area.
When you water, shut down the system as soon as water starts to run off; regardless of any other consideration. Watering beyond this point is wasteful.
Each irrigation should wet the soil for at least the top 6", preferably 12". So, if runoff occurs before this depth is reached, a second watering should be done in the permitted day.
