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 at this time, 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 winter 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 fine (yet almost impossible to find at garden centers) but I commonly see winterizer fertilizers with ratios of 30-0-10…way too much nitrogen in my opinion.

If you fertilize your bermuda lawn regularly in summer, you could get by with a half-strength rate in mid-September. As fall progresses though, less benefit and more harm is possible after applying a winterizer.

See these sources for more information:

When to Winterize – Georgia

Winterizing Lawns – Clemson

Why you should not winterize your lawn – Auburn

The Myth of “Winterizer” Fertilizer – Colorado

Do You Need to Use a Winterizer Fertilizer on Your Florida Lawn?