True. But there are two things that you didn't consider: 1) the grass definitely wakes up sooner/greener in the Spring if the Nitrogen is already in the plant, 2) if you fertilize in the Spring, weeds get a nice share of the fertilizer -- not so if it's already inside the grass roots and stored.

I used to thing the late fall app of "winterizer" was a bunch of hooey. Why? Because I like to look at Mother Nature's methods of lawn and soil care. All She does in the fall is drop leaves. She does not drop high N, fast release chemicals. But people like Andy and a few others have convinced me that it actually works when the right fertilizer is used at the right time. IF you want the lawn to come out early in the spring, they applying a high N, fast release chemical fertilizer after the grass has stopped growing seems to work. Early spring greening is not one of my goals, so I have not tried it. But Andy and the others have been around more than a few springs to watch and see what happens with and without winterizer. I have learned a lot from him.

In the early spring, once your lawn awakens, it is going to grow fast no matter what happens. But if you fertilize in the early spring, instead of mowing 2x per week, you might need to mow 3x or sometimes 4x per week just so you don't mow more than 1/3 of the height off.

Another issue is the early spring fertilizer cranking up the metabolism of the plant so that it uses too much of its stored nutrients. If that happens, then later in the spring when the soil nutrients and chemical nutrients wear out, the grass plants crash. We see that here a lot. People write here in early May saying, 'my grass did great after I fertilized in March but now it looks terrible.' Happens all the time. It is much better to fertilize after that initial flush of new grass has slowed down. Then the fertilizer helps replenish the lost stores of nutrients.

Another issue is wasting your precious lawn hobby money on unneeded applications of stuff.

Another factor in the fall app of fertilizer is that the soil microbes are always doing something. We are a long way from knowing everything that happens in the soil over the winter, but clearly there is a 'reset' going on. Magical things happen in the spring that no combination of chemicals, water, or organic applications can repair from the previous season. Somehow the grass comes in deep green and growing hard. Just warm up the soil temps, add spring rains, and miracles happen.

This is an interesting topic. As mentioned in a different post, I'm not a lawn expert, but would like to figure out WHAT kinds of fertilizers and week killers to apply to my lawn and when to do it?

Problem is that there are so many different formulations on the market its difficult to know what to apply and when to do it. I will have to do more reading here and do some searches to fiogure out what the members here suggest.

Thanks.

Thanks for the info! It makes a lot more sense now.

There are a lot more advantages to early Spring green-up than just visual appeal.

When I reread my previous posts and see all the typos, I want to just up my dose of meth to forget about it. Sorry for that - I hope you got the gist of what I was saying.

Yard guy, if mop708 is happy with his replies, I can address your issue. Keep in mind, though, that your question is slightly different from mop's, so some people might not come here to answer you.

Generally chemical fertilizers are applied 3x per year. One app is put down in late spring, and two are applied in the fall. One of the fall apps comes at the end of summer when the evening temperatures start to fall. The last app of the year is the winterizer mentioned above. It is a high N, fast release, fertilizer applied right after the grass has stopped growing. Your mower will tell you when that is. The formulation of NPK is less important than you are making it out to be. If you are really concerned, get a soil test. N will always be needed. The amount of P and K can vary depending on what your background levels are with your soil. There's a little more to it if you want to become the yard of the month a couple times a year.

If you want to use organic fertilizer, then that's a different topic. You can apply organic fertilizer any day, or every day, of the year. Organic fertilizers work by feeding real food (like corn, soybean, wheat, alfalfa, cottonseed) to the soil microbes. The soil microbes process the food and turn it into real plant food. This biological process (miracle?) was not understood at all as recently as the mid 1990s, so all previous thoughts about organic gardening are based on immature science. Modern organic gardening does not stink, kill the plants, or cost an arm and a leg. About the only noticeable difference between chemical and organic fertilizers is the organic ferts take a full 3 weeks to complete the biological cycle and make the grass green. Thus you should anticipate the need and fertilize 3-4 weeks prior to your daughter's backyard wedding. Another difference some people have noticed is that organic fertilizer weighs more. A 50-pound sack of alfalfa pellets (rabbit chow) will cover about 2,500 square feet whereas a bag of chemical fert covering that area only weighs 8-10 pounds. Nowadays the cost is about the same. It used to be the cost of organics was about $75 per 1,000 square feet per year. Now the cost per year is more like $15-$20. Cost of chemical fertilizers is roughly $12-$15 per 1,000. Back in the early 2000s when this concept of biology replacing chemicals was just becoming understood, the arguments on this forum between organic and chemical folks were very nasty. It became so bad that they started a separate organic lawn care forum just to try and keep us separated. It sort of worked but since then, I published something called the Organic Lawn Care FAQ. Once that went viral (as much as lawn care advice goes viral), all the arguing stopped. People tried it and found it worked. It is hard to argue that something doesn't work when it does work. More recently, in 2010 mrmumbles posted the following picture on this forum.

{{gwi:79339}}

He applied rabbit food in the green spot in mid May. The picture was taken in mid June. Note the improved color, density, and growth. It's hard to argue that something doesn't work when it works. That photo has sold tons of alfalfa pellets. I see it on the forums and even at my own feed store. They all seem to know about using alfalfa on lawns.

"There are a lot more advantages to early Spring green-up than just visual appeal." by, grass1950.

My understanding is that early green up that is 'forced' by immediate access to water soluble nitrogen would burnout the plants early and diminish the normal root development of that time of Spring.
What 'advantages' are you referring to for timing?

I was refering to the early Spring green up due to the application of a winterizer. Although theories as to "why" abound, there is observable improvement in Spring spreading and thickening of KBG, and studies consistantly indicate measurable increases in root mass of winterized turf vs turf that does not receive a late Fall N app.
In lieu of a winterizer application, the advantages of a Spring application of N likely outweigh the disadvantages as most university turf programs so advise.

Thanks for the clarification. That is in line with what I've been hearing too. :)

In addition, the earlier you have dense top growth, the fewer weeds you can expect.

"In addition, the earlier you have dense top growth, the fewer weeds you can expect.", by dchall.

The thinking for northern grasses is that fall and spring are for root growth. The dense root mass will increase weed competition and lead to the top growth when the time is right for that to happen. Early spring fertilization interrupts the timing for both the root and the top growth thereby weakening both. :)