We NEVER cut below 4 inches on St. Augustine under normal maint. conditions. The reason is simple, you can figure as a rule of thumb that every 1/4 of inch you can give it on top growth can equate to 1/2 inch root growth possibility. The turf does not seem to use its resources to struggle to put on that growth again and therefor IMHO seem to retain a deeper green than a lawn facing similar conditons being cut shorter. This all my not be accurate in terms of color retention etc but it sure seems to be the case in neighborhoods were neighbors share the same fert company and have dwellings face the same exposure yet our lawns appear deeper green than the homeowners who cut there own lawn (of course at lower heights with residential push mowers). Currently we are mowing most of the healthy thick looking lawns at 4 3/4 and some at 5. The highest the mowers will go without being in transport mode is 5 1/4 and we were mowing many at that height last year in August as I recall when the heat was on. If you are doing the best you can to assist your pest control company you are or should be cutting high as possible to follow the "1/3 rule" as closely as possible. This is known to also help lower the chance of the lawn becoming too thatchy. I know it is never possible to follow it 100% but generally speaking if you are cutting at 4.75 or higher during the hot rainy season...you are cutting the least of the leaf structure off because you know darn well in the heat of the season if you come in and are mowing at 4 inches or lower you are just saying the hell with that rule because the rapid growth rate during that period of time. We have no issue with Palmetto or Seville being cut at this height either and looking good. Especially Seville as unless installed incorrectly (in full sun) then you are most likely using it on a partially shaded or shaded lawn and leaving it long of course allows for more of the leave structure for root depth as well as photosynthesis. For those of you planting Seville in full sun you had better be ready to have a extra spongy lawn in a couple of years especially if the home owner is a active waterier and also it seems to be much more spongy in full sun if the fert company is using a quick release fertilizer. In many lawns that have patchy growth patterns cutting tall allows all the turf to catch up and eventually a lawn that once looked patchy because of irregular growth now look like carpet. My only reservation about cutting this tall during rainy season is if the lawn has a history of severe GLS fungus. A good sections of lawns will start showing signs of this disease during the rainy season and I have never gotten a confirmed answer from anyone as if cutting too high during this period may lend conditions that favor this disease as by cutting this high you are also potentially limiting air movement through the leave structure. I would appreciate hearing from any PCO that would want to give their thoughts on this possiblity.