Q: I heard you say on radio that it is not necessary to apply a winterizer to bermuda lawns. Why not?
A: Mostly because you will be wasting your money except in limited cases. Bermudagrass starts slowing its growth rate in mid-September. It begins storing nutrients in its root system, to use at next spring’s greenup. If you apply fertilizer now, you’ll force the grass to take nutrients out of its roots in order to grow new green shoots. This sends the grass into winter with less reserves than it needs to withstand cold damage.
What’s needed is a fertilizer containing low amounts of nitrogen (the first number on the bag) but higher amounts of phosphorus and potassium (the other two numbers). A 5-10-15 would be great but it’s almost impossible to find at garden centers. I commonly see winterizer fertilizers with ratios of 30-0-10…way too much nitrogen in my opinion. My recommendation is to stop fertilizing bermuda and zoysia lawns in early September. I have references to back up my point at http://www.walterreeves.com/gardening-q-and-a/winterizing-warm-season-lawns-not-necessary/.