No matter the time of year grasses should not be fed when that could induce new growth that could be stressed which causes more problems than not feeding that grass would. Provided there is not any snow on the ground I have lots of time yet, 'til Thanksgiving, to feed my lawn here so you could well have until mid December. I'd not be in a hurry to fall feed, as long as it is done before the grass is covered with snow, something kind of hard to judge up here.

Maybe I'm rading the question wrong, but IMHO you want some warmer temperatures for protein based fertilizer because your microbial action will be greater. 86 is too hot for me to walk around spreading sbm. 60-70 is a sweet zone for me and the microbes. Below 50, it takes a long time to see results. Don't forget to take into account the time it takes for results to show - about 3 weeks if that is a consideration.

When applying a fall fertilizer what you want is the nutrients you spread to be stored by the plants, that are going dormant, so in the spring as they start new growth they have ample nutrients to sustain that growth. What you do not want as your plants are going dormant is to force new growth, so any fertilizer would need to be spread at a time to do that. The roots of all grasses do keep growing for some time after top growth stops.

Thanks for the input here. So I'm getting from kimmsr that the fall fertilization is primarily to provide nutrients for the root system through the winter and give it something to snack on once it starts growing again next spring, not for any visible benefit this fall, and that I should wait until it temperatures fall to the point where growth will soon stop for the season. If I understand soccer dad correctly, I shouldn't wait until temps drop too much as it's the microbes doing the work and they go on vacation in cold temps. So I guess the question remains -- at what temperature should I fertilize?

What type of grass? How long before your first frost? If I understand your original question you want to apply a fall feeding of protein to promote growth and green color. If that is not the case, then I'm missing something. If that is the case, apply now.

A fall feeding and a winterizer are 2 different things, but IMHO are irrelevant to protein based feeds. September, October, November are optimum months to feed cool season grasses.

>What type of grass? How long before your first frost?Soccer_Dad, it's a tall fescue blend. First frost usually comes right around Thanksgiving.

>A fall feeding and a winterizer are 2 different things, but IMHO are irrelevant to protein based feeds.Ya lost me on that last part. The lawn looks great now, I just want to do what's best for it so it'll continue to thrive next spring. If I went ahead and applied SBM now, would I be benefitting the look of the lawn for the short term as well as benefitting its root growth over the winter? BTW, typically we don't get down to freezing until late December or early January.

Some people think that a frost stops all soil biological activity when it does not, they seem to think that a frost causes the soil to freeze solid when it does not. I have had probably 6 frosts here and my soils temperature is still 50 degrees, because it takes quite some time of low air temperatures to get the soil temperatures that low. Many years, here, I have mowed the lawn Thansgiving week because of the growth, and that alone indicates that soil temperatures are not low enough to stop growth. The first several snows, although it may accumulate on the grass during the night, usually melts because the soils temperature is still too warm to allow snow to accumulate, although one year it snowed the first part of October and the snow stayed until mid April, too much snow at one time. So just when do you fertilize? Difficult to say for sure but do so when grass growth slows anough to indicate it is starting to go dormant.

>So just when do you fertilize? Difficult to say for sure but do so when grass growth slows anough to indicate it is starting to go dormant.Works for me. Thanks to you both for your patience and for sharing your wealth of knowledge.

-Ray