I would apply the last fertilizer of the season when the top growth has stopped, but the grass is still green. I'm not sure when that is where you are, but I would guess it would be late November.

I would also probably apply something other than the name brand winterizer.

For one thing, the store brand or generic with the same NPK numbers is just as good as far as the grass is concerned.

And the second thing is that although conventional wisdom is that a high Phosphorous (the middle number) percentage is needed for good root growth in a winterizer, recent research has shown that Nitrogen is actually the most important component in a late fall fertilization. Since top growth has stopped, but the grass is still green, it is still photosynthesizing, and all the energy is being stored in the roots.

So my advice is to apply a pound of N per 1000 sq ft after the top growth has stopped. If you can get urea (something like 46-0-0) or ammonium sulfate (21-0-0), those are fine. The best thing you can give your grass for the final feeding is the nitrogen.

I haven't seen the new nitrogen recommendations that bp was mentioning and there may very well be something to what he said, but in my area right now it's thought that if you don't have a soil test that specifies what to apply, a complete fert (4-1-2/3-1-2) is probably the better bet. Just my $.02

Without a soil test, youÂre flying blind. I agree with bpgreen, high nitrogen fertilizer application after the top-growth stops. Jimtnc also eluded to the need for a reliable soil test. And IÂm sure the number he stated were proportions not actual number recommendations. 30-10-20 for example Every homeowner who is enthusiastic about his or her lawn should have a soil test periodically. As a minimum you need to know the PH and the Phosphorus and potassium needs. Bill Hill

Yep, they were proportions for NPK. I suppose applying a high nitrogen would be okay at the end of growing season since that's what would be stored for the winter. How high is reasonable? Don't know that, but NCSU still insists on a complete fert. Anyway, that's what they say.

phortres,

I applied the following this fall and need help deciding when to put on my final application of Scott's Winterizer:

Here is some information from the Scotts Step 4 (Winterizer) product page that might be useful.

(Apply as Step 4 in Scotts Annual Program  apply in fall (August-November). Early fall fertilization will provide maximum fall color and growth. Mid- to late-fall fertilization will give extended fall/winter greening and more early spring response).

Thanks for all the help. I will get a soil test done.