Also, we provide leaf removal for many of these customers that need winterizer. I need to time the application after a leaf removal is complete. Otherwise, we run the risk of blowing and vacuuming up the fertilizer.

 

Good question: has anyone seen any proof as to what percentage of fertilizer can be picked up by leaf removal?

The ground does not freeze after a few frost events. The thick grass acts like an insulating blanket. I think you are fine to go ahead; apply the winterizer. Temp is 30 here. I looked at your weather forecast: says it will be 66 on Saturday. It would be best to apply a slow-release fert to reduce chances of run-off. Also, you should go with a non-phosphorus fertilizer as run-off from phosphorus is the main cause of environmental degradation. No-phos is the law in my state.
A fully-coated all slow-release nitrogen would suit your situation. More cost--more results.
Potash is water soluble--it might leach out after an inch or two of rain--a waste. Wait for spring on the potash.
Maybe this:
https://www.kochturf.com/products/slowrelease/xcu/

Or...it is likely a Knox XRT 44-0-0 fully coated, would suit your needs.

http://www.kmb.us.com/products/xrt/literature/labels

 

I hate to disagree with my friend @RigglePLC, so let me say that I would just like to offer an alternative suggestion. Most "winterizer" fertilizers are blended to contain large amounts of fast release nitrogen. The theory being that the nitrogen becomes available right away so that the grass can use it quickly before the ground freezes. Any slow-release nitrogen that releases after the ground is frozen is unused and just gets washed away. This late in the season a half pound or less per K should be enough.

 

Let me just add that I think Riggle's slow release suggestion is well suited for earlier applications in October.

 

I am using 24-0-0 at 4lbs per k. Thrive brand 7.2% Ammoniacal nitrogen
16.8% urea
8.25% sulfur

I can’t determine whether or not it is all slow release or not.

The ground was frozen at the top but thawed today. I got some jobs in.

 

I am using 24-0-0 at 4lbs per k. Thrive brand 7.2% Ammoniacal nitrogen
16.8% urea
8.25% sulfur

I can't determine whether or not it is all slow release or not.

The ground was frozen at the top but thawed today. I got some jobs in.

That's a fast release fertilizer unless it's coated. I think you only need to use 2lbs/k of that fertilizer and you'll be putting down 0.5 lbs/k total nitrogen.

The package label should say what percentage of the nitrogen is slowly available.

 

Several States have a cut off date for applying fert. Here in NJ, Nov 15 was the last day for homeowners, tomorrow is the last day for professionals. These restrictions were put into place to reduce nutrient run-off.

 

From my experience fert really doesn't get sucked up by mowers or blown around once it hits the ground.

I only wait until after cleanup to do our last app for customers who are worried about it to make them happy and keep their business.

 

And I'd like to add that our last app is elemental sulfur so if a significant amount of it was being lifted by mowers it would be very noticeable by the crew, burns the eyes and throat when it's dusty.

 

But it is not too late to apply fertilizer now?

 

I see no problem putting the late season out anytime before the ground is completely frozen. The idea being that you would like to maintain good photosynthesis, if possible, when air temps are above 40 degrees in the winter and early spring. As long as the plant is still green it can produce carbohydrates that are stored in reproductive parts of the plant thus expanding the root system and rhizomes. The benefits of this application will be most notable in late winter and early spring before leaf tissue growth begins. A very critical place where the late season application is needed is in shaded areas of the lawn. November until May is about the only time of the year that these turf areas receive direct sunlight for photosynthesis. These areas should get heavily fertilized at this time. Density and rooting will be quite noticeable from late February through April but by June these shaded areas will go into survival mode as photosynthesis is diminished. My observations is that two to three weeks after leaf cover on the trees, this grass will become more spindly and the root system will weaken. Get it while you can!

 

That's some good thinking on grass in shaded areas. I'm going to remember that.

 

Thanks! This is my shade lab otherwise known as my backyard. Multiple species of grass grown at various heights. Other than the putting green, all other locations only get mild fall fertilization then followed by a heavy late season feed. Never fertilized at any other times. I spend a lot of time here all season and see the grasses transform very quickly with leaf cover in mid to late spring. Chipping off these surfaces in the early spring causes no damage but by June the divots and chunks of grass just fly. No roots or lateral strength. Leaf blades become spindly and diseases can setup. Water is used sparingly and only when absolutely necessary.

 

Rain is predicted --it will melt our 4 inches of snow--maybe.
Hopefully I will have a chance to test some winter fertilizer on some 1 sq yd plots.
And later, can you put fertilizer on top of snow? Of course, but will it do any good? Any harm?
Probably one needs to crank it out with a chest spreader. Or a hand held spreader.

Soil not frozen here--not much anyway.
I just checked--easily penetrated with screwdriver. Deeper layers retain some heat for a few weeks.
What about your city?
http://www.greencastonline.com/tools/soil-temperature

 

I usually have my last application on by early to mid November. This year it was later due to the crazy weather. However, I’ve never worried because we usually get some snow cover before the ground freezes, giving it some insulation and allowing it to absorb. I also believe that, unless it’s a significantly slanted yard, most of it will make it into the soil before it has a chance to run off. It seems to hang in the soil until spring thaw and helps with quicker green up.

 

I could not find the "Thrive 24-0-0" fertilizer you mentioned. But if it contains sulfur--probably some of it is sulfur-coated urea.
This is good, because coated urea is not much susceptible to loss due to leaching.
Can you apply fertilizer over snow? You probably need a hand-held or organ-grinder type spreader. It is easy. But will it do any good. And will it degrade the environment?
I did a small test, just a few sqft. Results in spring.
Compared Milorganite and Turfbuilder.

 

Lime on top of snow; sure why not? Pushing the spreader becomes the problem. If it fits your schedule better--should work fine.

Organic fertilizer on top of snow? Either case, could be difficult to spread. You may need a chest-carried hand-crank spreader.
https://earthway.com/product/2750-nylon-bag-seeder-spreader.ashx

However, with lime you need a lot; repeated trips over the property may be needed.

I did a small test (6 feet by 6 feet) comparing Milorganite and Scotts Turfbuilder on top of snow, which then melted in a day or two. Snow does not melt instantly. Moisture appears to gradually sink into the ground.

 

I know of golf courses that put out there organic fertilizers on top of the snow in winter to avoid any complaints of the smell during the golf season. One thing to remember about organics is they aren't late season or dormant feeds. They are warm/humid season feeds because that's when they go to work. People load up their turf in the late fall with these and don't realize that and start loading nitrogen on top of a bank account of nutrients and this can blow up during wet/humid/hot periods during the summer.

 

Organic products often depend on soil bacteria to decompose and release the nitrogen. This works only when the soil is warm enough for bacteria to work. This is good. Except that the phosphorus is too high.
Urea nitrogen, if not taken up by the roots, can be leached out by heavy rains, or snow-melt moisture, and potentially raise the nitrogen in ground water. Slow release reduces this problem, but sulfur-coat releases nitrogen even if the ground water is cold.
Since Scotty has convinced the general public that "Winterizer" is a good idea--we might as well take advantage of their advertising push in the fall.

 

According to most university research that I have read, you can put down a winterizing fertilizer when soil temperatures are between 40 and 32 degrees. After the shoots quit growing the roots begin to store carbohydrates for the winter until the soil freezes.

That doesn’t work out so well sometimes here in the Minneapolis area. This fall I had only ten days of soil temperatures between 40 and 32 degrees. Last year we had about three weeks, but it can be difficult to tell when the temperature is going to go below 40 and stay below 40 and how long it will be before it freezes and stays below freezing. In either case, it can be difficult to get the fertilizer down with enough time left to work and be used up before the ground freezes.

An interesting thing about Scotts Winterguard fertilizer is that it contains quite a bit of slow release methyleneureas, 6.8% of the total N in the bag. Why is that there? Maybe it’s because the whole name of the product is “Turf Builder Winterguard Fall Lawn Food”. Notice the word “Fall” in the name. I’m not sure where the term “Winterizer” came from, but the Scotts company is certainly using it to sell their product.

 

I meant to say that 6.8% of the 32% total N in the bag is methyleneurea or about or about 21% of the total N. I hope I'm saying that right.

 

The words, "winterizer", and "dormant feed", should only be associated with chlorophyll. It's the chlorophyll that is responsible for carbohydrate production during the winter dormant period. These carbohydrates produce the reproductive tissues of the plant since top growth has ceased. Timing this feed while the leaf tissue is still green but not growing shoot tissue lessons the likelihood of succulent growth that could lead to snow mold and possible desiccation. Anytime the air temperature is above 39 degrees and the plant is green, it has the opportunity to photosynthesize. Cold, desiccating winds can bleach the chlorophyll during the winter and the benefit is greatly diminished. Certain years produce great opportunities for dormant feeds and yet other years will show harsh conditions and snow cover that inhibits carb storage.

 

Interesting discussion. I did my last app on Nov. 23. Timing is more driven by a schedule than weather for practical reasons. I was glad to put the spreader away for the season. Now Fall cleanups and landscape bed maintenance dominate.

Couple of things I’ve heard or read over the years — maybe folklore or maybe valid. I don’t know for sure. Here goes — use amonium sulfate based N in late season because it’s the ammonium form of N so is immediately plant available. Cool season grass drastically slows or even stops top growth at soil temps around 50 degrees F. Cool season grass is basically done metabolizing at soil temps below 40 degrees F. Fert apps stop when soil temps are or are forecast to drop below 40 because it’s pointless and risks N runoff or leaching. Fall N is the most important for cool season grass (I’ve heard a number of justifications for this and they all make sense).

A question that pops up in my mind often enough is how long it takes a plant to “wake up.” So assuming it’s right that the plant shuts down at 40 (or whatever the right answer is), if the soil warms above that temp for only a day or two, does the plant do anything, like wake up and have a quick snack before going back to sleep, or is a more sustained period of the warmer soil temp needed? I know it needs and uses water all Winter so it must be doing something.

 

Hineline makes a good point--photosynthesis can continue even when the temperatures are well blow 40. In theory, food in the form of starch and other carbohydrates can accumulate--and be stored for spring.

As for wake-up time--don't know. But I am sure liquid water is necessary for cellular reactions to take place. No yawns nor stretches needed.

 

Don’t forget about the light component of photosynthesis, Day length and intensity are also part of what tells a plant to slow down or wake up. I don’t think I remember having ever heard this part of the equation being discussed with fall fertilization, but I do recall reading about its participation in the hardening off process that grass goes through before winter dormancy.

 

Why not do a liquid application that way it gets to the roots faster via the leaf and you don't have to worry about leaching and runoff?

 

That would seem to make sense, I just wonder why I've never read about that?

 

I don't know how you guys get the idea that liquid fertilizers leach out or run off less than granular.

Like Kerb said unless you are spraying micro amounts solely as a foliar app the bulk of the spray is going to go into the soil where it'll be just as vulnerable to being carried away by water if the plant doesn't take it up as anything else.

 

I don't know how you guys get the idea that liquid fertilizers leach out or run off less than granular.

Like Kerb said unless you are spraying micro amounts solely as a foliar app the bulk of the spray is going to go into the soil where it'll be just as vulnerable to being carried away by water if the plant doesn't take it up as anything else.

That's exactly what I am referring, too, a foliage app vs granules sitting on the soil.