Slow release won't hurt, but may not help as much as fast-release dropped when the grass stops growing.

If you can't save the slow release for next year, then feed on November 14th with it. It's much better than nothing.

I looked at Home Depot website and the Miracle Grow Lawn Food is described as fast release. If the grass has stopped growing (when you mow, no grass is cut), you can apply the winterizer fertilizer.

Thanks.

So miracle grow's version of winterizer is fast release, or do you mean that I can use any winterizer fertilizer (scott's?) because they are generally fast release?

Still not sure I get the timing. Grass growth has slowed down, but we could have no growth for a week or two in November and then sudden growth in december if we get a warm week. Maryland is weird like that. Are there any other signals that it's time to do the last fert? Does an upcoming week that averages 40's during the day and 27 low at night mean it's time?

Any good articles on this practice?

You can use any fertilizer that is mainly fast release. Look on the label to see what percentage is WIN (water insoluble nitrogen). For this you want no WIN or as little as possible. The slow release is just wasted because by the time it could be used, the plant is dormant. As for timing, if you go 2-3 weeks with no growth, it should be fine to apply. When do you put your lawnmower away for the season? I'm in Virginia and we too have warm days in December (and into winter) but for me there is usually no more growth by late November/early December. You want to apply before the ground freezes (when it's hard to dig because it's frozen) and that shouldn't happen for awhile, so there is no rush right now. So just keep watching the growth. The optimal time is soon after shoot growth stops. As for articles, do a search for "fall nitrogen regimens cool season grasses."

Everybody freaks because winterization is the most difficult to gauge in terms of when to apply--and because grasses that stop growing can start to grow a little again afterward if temperatures spike.

No worries. That application of fertilizer would have fed the lawn perfectly well during the six weeks of maximum growth. Even if you mis-time it a bit, or it re-warms, you're fine.

Growth hasn't quite stopped on my lawn, and won't until late in the month. But even if I applied it right now, I'd be OK. I wouldn't get 100% benefit from it, perhaps 90%...but 90% is still good enough, and many times better than if I did nothing.

Thanks for the info. I found this site:
http://aroundtheyard.com/northern/fall-nitrogen-regimens-t15109.html

Please check me on my understanding of the "easy" form of this program:

Early Fall
- For the Northeast, wait until around Labor day (September 7), after the grass leaves it's dormant stage, begins browning off/shedding, and then begins to perk back up
- apply slow release fertilizer, as this point is about 6-8 weeks from the first frost (10/17 this year or my town according to the internet)

Mid Fall
- after first frost (10/17 this year), allow grass to slow down
- no Nitrogen applications should be made.

Late Fall
- Continue mowing until you see no more top growth
- roots will continue to grow and store nutrients for 3 more weeks\
- apply Urea pure (fast-release) Urea or Ammonium Sulfate at 1 lb/1000 sq ft of Nitrogen which is a tiny bit more than 2 lbs/1000 sq ft of 46-0-0

Notes:
- Applying Winterizer too early will cause top-growth to continue, which can cause Winter Kill and damage to the grass
- Don't use of a fertilizer containing Potassium after first-frost. There is at least one study that indicates that this can increase Snow Mold occurrence.
- Using slow-release fertilizers for Winterizer is not a good idea. The short window of root-only growth may not get all the benefit and nutrients from the fertilizer before root-growth stops.

So now I just have to find true fast release fertilizer, figure out when the grass stops growing...and time that with my free time, and when I have time to get the leaves off the grass so that the fertilizer can reach it. sigh...

This post was edited by viche on Mon, Nov 10, 14 at 17:51

Oh I forgot to add that the article mentions:

"Make sure to water in any fast-release fertilizer applications - don't rely on "predicted" rainfall."

It looks like I'll need to take a day off from work. No way I'm gonna water the entire yard at this time of year.

If rain looks pretty certain when it's time to winterize, I'd go for it instead of watering. Mow your leaves. That is valuable organic matter for your soil. Today I picked up leaves from the street and spread them out in the backyard to mow in. This is the third time I've done that this fall. You will be surprised at how many leaves can be processed this way. It took four passes to get them shredded into tiny pieces but it's easy to do and is great for the lawn. If you want to try to find urea, you may find it at a farm supply store.

Meh, I tend to run with expected rainfall or wait for the next one.

Outgassing, even in an alkaline environment, isn't that extreme when temperatures are low. As long as it rains in a week, you're golden.

Twenty percent losses on winterization are tolerable, particularly if you went to 1.25 pounds of N per thousand (right in the middle between the OK and high ends of winterizer nitrogen level recommendations). That'll take a lot longer at 45 degrees than ten days.

Here is a link that might be useful: Urea volatilization by pH and temperature

Beck, yeah I plan to wait for rain, but the chance of it raining on a Sunday or Monday is lower than it raining Tuesday through Saturday so I see myself having to take a day off during the week to do the work. Unless, as Morph suggested, I don't worry about immediate irrigation.

Regarding mulching leaves. My mower does a crappy job of mulching. I need a high lift blade and mulching baffle kit.

Don't the bits of leaves tend to shield the soil thereby increasing runoff and decreasing fertilizer absorption?

Don't the mulched leaves change soil PH or leach nitrogen from the soil during decomposition?

Morph: Thanks for the link. I had no idea that the concern was evaporation. Good news is that after tomorrow we won't see 60 degrees again, and my soil is definitely acidic. So other potential evaporation, delaying irrigation has no impact on the health of the grass? Like it won't burn the grass by sitting on the foliage undissolved?

So what should I ask for when I call farm supply stores? Pure, Granularized Urea? 46-0-0? Fast release nitrogen fertilizer?

Also, how careful do I need to be about not overlapping. What will cause the grass to burn? I've never used quick release before.

Sorry for all the questions. When I do something, I don't like to make guesses.
Thanks all!

I have a regular lawn mower with side discharge. I mow in concentric circles one way for a couple of rounds and then mow in the other direction for a couple of rounds and keep switching direction til I get to the middle. Then I start in the middle mowing to the outside, and if it still needs more chopping, work from the outside in. I've never heard of any problems with fertilizer applications because of mulched leaves. The mulched leaves will help your PH. The leaves provide a little bit of nitrogen. You will be feeding the earthworms and other soil creatures that you want in the soil. It doesn't take long for them to consume the bits of leaves. I have picked up leaves from the street to spread (thickly) on the backyard three times this fall to mow in and will likely do it one more time (only have a small tree in the back).

If you go with urea, use 2 lb per K. Put your spreader on a low setting and spread back and forth (like north/south) and then switch directions (like east/west) and keep going in alternate directions til it's gone. Urea is 46-0-0. Unless you have a very big yard, you may be able to do this early before work if rain doesn't come on weekends.

>>Regarding mulching leaves. My mower does a crappy job of mulching. I need a high lift blade and mulching baffle kit.

My robot does a great job, my Toro not so great. It really doesn't matter as long as the leaf is torn apart and isn't much larger than a third the original size.

>>Don't the bits of leaves tend to shield the soil thereby increasing runoff and decreasing fertilizer absorption?

Nope. The smaller leaf bits can't shield very well and tend to end up vertical in the grass profile anyway. Water makes it in just fine and I've never noticed any issues at all.

>>Don't the mulched leaves change soil PH or leach nitrogen from the soil during decomposition?

Nope. Good news--they're at the surface, so they can only take nitrogen from the soil surface to decay, or the air. Usually they grow a nice set of nitrogen-fixing bacteria and take it from the air, adding to the net nitrogen slowly over time.

The pH of decayed leaves, even the dreaded oak leaf, is very close to 7.0 at the end of the road (although decay itself will initially be acidic). The upshot is no change to your soil pH, or even a slight moderation toward neutral.

The mass of leaves you'll add, even if you import, isn't great enough to make any appreciable change anyway. I imported close to 1,000 pounds of leaves one year...which got spread over half a million pounds of soil.

>>Morph: Thanks for the link. I had no idea that the concern was evaporation. Good news is that after tomorrow we won't see 60 degrees again, and my soil is definitely acidic. So other potential evaporation, delaying irrigation has no impact on the health of the grass? Like it won't burn the grass by sitting on the foliage undissolved?

Definitely apply on dry grass as bits clinging to the grasses can burn them in that spot. But other than that, you'll be fine.

I try to time with rainfall but...well, that doesn't always work out So far, no problems. Ever.

>>So what should I ask for when I call farm supply stores? Pure, Granularized Urea? 46-0-0? Fast release nitrogen fertilizer?

Urea will be cheapest...but touchiest in terms of application. High nitrogen, fast release fertilizers are common, and lower in N than urea is (I use 29-0-5).

I tend to get the cheapest one of those.

>>Also, how careful do I need to be about not overlapping. What will cause the grass to burn? I've never used quick release before.

Severe overlapping will burn--so I usually recommend a broadcast spreader, where overlapping is expected and required to get the correct amount down.

On the up side, burn potential in November is extremely low. Acceptable rates are 1.0 to 1.5 pounds of nitrogen (bag rate on all synthetic fertilizers), but that has a built-in margin for error.

Got it...thanks for the additional info. I have a VERY unflat yard, so robots and mowing/fertilizing in multiple directions is not practical.

Is the "High nitrogen, fast release fertilizers" something I will only find in farm supply stores?

So I calculate my K's of square footage for my yard, set the spreader to low, and just keep making pass after pass over the entire lawn until I use the appropriate amount of fertlizer. 2lbs/K of straight Urea.

Assuming there aren't spreader settings on the bag, how do you figure out what 1lb of nitrogen/K is when using something like a 29-0-5?

I guess I'll just ignore this:
"- Don't use of a fertilizer containing Potassium after first-frost. There is at least one study that indicates that this can increase Snow Mold occurrence"

>>Is the "High nitrogen, fast release fertilizers" something I will only find in farm supply stores?

Any big box store will have them, plus almost any Lesco, landscaping outlet, garden store, or other retailer. Even my local K-Mart and Wal-Mart stock fertilizers.

If you choose a name brand, choose an off-prime one like Vigoro. Or just get store brand, which is made by one of the big guys and will be a lot cheaper.

>>So I calculate my K's of square footage for my yard, set the spreader to low, and just keep making pass after pass over the entire lawn until I use the appropriate amount of fertlizer. 2lbs/K of straight Urea.

Correct, although the target will actually be 2.2 to 3.3 pounds. Anywhere in that range is perfect if using urea, 45-0-0.

>>Assuming there aren't spreader settings on the bag, how do you figure out what 1lb of nitrogen/K is when using something like a 29-0-5?

For 1 pound of N, multiply by 100 to get 100 and divide by the N level, so:

100/29 = 3.45 pounds. 3.5 is more than close enough.

For 1.5, do the same, get 150 and divide by the N:

150/29 = 5.17. In this case, I'd error low and call it 5.1.

So for 29-0-5, your target is anywhere between 3.5 and 5.1 pounds per thousand square feet. Going slightly over or under isn't a problem.

>>I guess I'll just ignore this:
"- Don't use of a fertilizer containing Potassium after first-frost. There is at least one study that indicates that this can increase Snow Mold occurrence"

It's not bad advice, but minor amounts of potassium where the N number is at least three times the K number are fine. It's not going to be a significant amount of K. In the case of 29-0-5, nitrogen is almost six times greater than potassium. No problems there.

Winterization is not the time to be applying a lot of potassium, however, so I would never recommend a balanced (10-0-10 or 10-10-10) fertilizer for multiple reasons.

In another forum I posed the question about fertilizer reaching the soil when there are mulched leaves and the answer was that the ferilizer dissolves in water and works its way through the leaves to the soil. So the rain (or irrigation) will resolve the issue of fertilizer getting to the soil.

Home Depot's website had buttons to search for fast release and slow release. That's how I found Miracle Grow there. They had some Vigoro there too but all were weed and feed. Your local store may have non-weed kinds. Call some places and ask what they have.

Okay great. The only one I could find on Home Depot's site was the Miracle-Gro Water-Soluble Lawn Food, but it's meant to be sprayed on. I don't see any other options there.

Lowes shows the following for fast release:
Scotts Starter: 24 25 4 (duration of feed is 2 months though)
Everything else had too much Potassium
Am I missing something here?

If I were to use the Scotts Starter I would do (100/24) 4.2 to (150/24) 6.2 lbs per 1000 sqft, correct?

That's a little scary to me since Scotts tells you to use their product at about 3 lbs per 1000 sqft (42 lbs 14,000 sqft per packaging)

Starter is definitely off the table for winterization. Adding K in November is bad.

Adding P in November is asking for trouble--environmentally, at least, as it doesn't have time to penetrate and tends to erode off, causing eutrophication in streams and waterways. Not to mention being a waste since you won't hold onto it.

Searching for "fertilizer" and selecting granule on Home Depot's site gives tons of results--most completely inappropriate.

Page 1, Scott's Winterguard 32-0-10 is fine, if a wee bit higher in K than I would prefer. It's not enough K to cause a problem.

On Page 3, Vigoro's Super Green is workable for locales where the soil doesn't reliably freeze (it's a product I've used here as I actively discourage soil freezing).

What I don't see listed--and my store always has--is the Vigoro 29-0-5 lawn fertilizer I've bought at Home Depot for years. Which proves the Web site isn't quite as comprehensive as one might hope. :-)

Yes I see all of the other granularized options, but all of them are marked:

Time release: Slow release

I realize I can use slow release, but if I'm going to do this right, I might as well use actual fast release fertilizer. I'm having trouble finding that though.

Were my calculations at least correct?

According to this, Maryland requires that at least 20% of nitrogen in fertilizer be slow release.

Here is a link that might be useful: Maryland guidelines

Maryland also limits homeowners to .9 lb of nitrogen per K for each application. Looks like you might as well use the fertilizer you already have before the deadline. Or maybe just skip it if you have applied sufficient fertilizer before now. Maryland isn't cooperating with the winterizing application.

Here is a link that might be useful: Maryland fertilizer rules

>>If I were to use the Scotts Starter I would do (100/24) 4.2 to (150/24) 6.2 lbs per 1000 sqft, correct?

Yes, that's correct!

>>According to this, Maryland requires that at least 20% of nitrogen in fertilizer be slow release.

I can see why. They watershed directly into the Atlantic Ocean and have rather sandy soil--my brother in law lives just outside Baltimore (which actually describes most of Maryland).

Given the climate there, and given the sandier nature of the soil, I have no objection to (and actually would recommend) Vigoro Super Green with 1/3 slow release nitrogen.

I've stood outside in Maryland on December 30th when weather here was classified simply as "bloody cold" and been entirely comfortable without a coat there. I'd never consider recommending Super Green anywhere north or west of my locale, but you're three hours by car south of me and near the (moderating) ocean besides.

In some years, it could theoretically backfire on the state if the ground does freeze, but they get around that with their date restrictions. Ground freeze will NOT be before January first, by which time the slow release N in anything is pretty much gone and in, with only potentially very minor amounts remaining.

So yes, go for it, use the slow release, and don't worry about it. The date is early enough for your locale, and given your locale, slow release actually makes a great deal of sense.

FYI, my soil is SUPER clay, and last winter we regularly had daytime temps in the 20s or below. This winter looks to be cold too.

If, as you say though, we won't freeze til January, my only concern is:
"Applying Winterizer too early will cause top-growth to continue, which can cause Winter Kill and damage to the grass."

I assume that doesn't matter as long as I don't apply until the grass stops growing....which now that I think about it, might very well be AFTER Nov 15 ( the mandated last day of fertlizing in MD). SIGH

Looks like I either need to break the law or just skip fertilizing.

BTW, is the super green at least lower in slow release than other bigbox fertilizers? I don't understand this comment:
"Vigoro's Super Green is workable for locales where the soil doesn't reliably freeze (it's a product I've used here as I actively discourage soil freezing). "

This post was edited by viche on Wed, Nov 12, 14 at 17:22

>>"Applying Winterizer too early will cause top-growth to continue, which can cause Winter Kill and damage to the grass."

It's not too early, so no worries there. Too early, in this instance, would be feeding it when temps like we've had would continue for another two weeks. They end tomorrow.

>>BTW, is the super green at least lower in slow release than other bigbox fertilizers?

Actually, it's about the same to perhaps a little higher. It's fine for use in Maryland, however--if I use it in PA, you're OK in MD.

Although looking at the longest range last year, I wouldn't've recommended it in PA, you'd still be OK in MD. This year actually doesn't look similar, it looks several degrees warmer.

Good news if it ends up being warmer. I HATE the cold.

So is the concern with using super green and freezing temps that, when the ground freezes, the slow release nitrogen will run off into streams?

What do you do to actively discourage soil freezing? :-D

Good news if it ends up being warmer. I HATE the cold.

So is the concern with using super green and freezing temps that, when the ground freezes, the slow release nitrogen will run off into streams?

What do you do to actively discourage soil freezing? :-D

I hear you. Last winter I practically hibernated from December to March. Even my lawn went partially dormant, but single digit temperatures aren't something you can do much about.

>>So is the concern with using super green and freezing temps that, when the ground freezes, the slow release nitrogen will run off into streams?

And with any slow release formula. It's also why I don't recommend heavy organics after October 1st anywhere in the northern part of the nation. Most years, they'll have at least six weeks to decay, minimum.

>>What do you do to actively discourage soil freezing? :-D

Raise organic matter levels. OM has a spongy, open, and more airy structure, so even if the surrounding soil freezes, the OM maintains channels into the soil where moisture and resources can penetrate without running off. OM's also happy to bind most resources for you.

Doing the above encourages worms, which also drill channels in your soil. Same effect.

Increase potassium levels to about 5% saturation. Like any ion, it turns down the freeze temperature slightly. Plus it armors the grass to tolerate cold temperatures quite nicely. Proper calcium and magnesium levels also help with freeze temps, but don't assist the plant in surviving cold weather.

OK, sit down for this one. Spray raw milk (pasteurized whole milk if that's all you can get) at 4 ounces per thousand square feet on your lawn once a year (more is just fine). Why does it work? Nobody has any friggin' idea. But it must be an enzyme as the effect lasts a year.

In a well-tuned soil, the effect is to increase grass' and gardens performance a little bit. It's obvious, but nothing extreme. In poorly tuned soils, tune the soil first before bothering.

But it also does something to decrease the freeze temperature. Soils maintain a flexible, spongy structure much colder than they would without it.

Why? Clueless. But it works.