Here in Zone 8 of SC, our warmseason varieties of sod are beginning to yawn, drink milk and cookies, and go to bed. The big winter snooze-fest. As Bob Ross might say, our soft little grassy areas are getting quiet for the coming winter. How do you get ready to go to sleep? Do you do jumping jacks just before you lie down to sleep? Drink an 8-hour energy? I bet not.
Well, guess what? The sod grass in your lawn doesn't especially enjoy getting pumped up just before bedtime either. When you apply fertilizer in the fall, you could have just as well given your grass a shot of caffeine. In general, don't apply nitrogen-containing fertilizer after around August 15th in the Upstate of SC or after around September 1st in the Coastal areas of SC. Let's think of nitrogen (the first number on the fertilizer bag: 10-10-10) as a growth encourager. If you encourage growth while the grass would otherwise (and naturally) be preparing to STOP GROWING, your human-ness is really screwing up your sleepy lawn.
As S. Cory Tanner puts it, "If you keep warm-season grasses awake and growing for too long into the winter, they will be half-awake and grumpy next spring." What a great comparison! If you live in the Upstate of South Carolina, you may not have "warmseason" turf. Just so happens, though, that here at SB Turf, Inc., warmseason varieties of sod such as centipede, St Augustine, bermuda, and zoysia, are the only types we sell. In a nutshell, that means they go dormant (aka, go to sleep) and turn brown during winter months.
The best thing you can probably do for your lawn now to help prepare it for sleepytime in the Pee Dee and coastal regions of SC probably has NOTHING to do with fertilizer and everything to do with mowing.
All sod / grass types have a mowing height that they grow best at:
Another way to help your lawn transition from the fall to the winter is by following a good fertility program through the active growing season based on soil testing. Potassium is known to give sod more cold-tolerance, but only if your lawn needs it. If an end of season soil test shows that your lawn is lacking, consider adding potassium using muriate of potash (0-0-60) or an organic source (hardwood ashes from an early fall fire in your fire pit).
Please, don't make sod insomnia a new problem in your lawn. Save fertilizing with nitrogen until after your lawn has emerged from sleep and greens up in the Spring. Thank you.