School me on Slow Release Fertilizer

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mvftw
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School me on Slow Release Fertilizer

Post by mvftw » August 9th, 2020, 9:25 am

I have read from this forum that Mid-August is a good time for Slow Release Fertilizer.
I have 2 Lesco Fertilizer's:
32-0-10 +2% iron 21.6% slowly available urea nitrogen
25-0-6 +5% iron 11.25% slowly available urea nitrogen
My math would say that 32-0-10 is a better slow release.
But are they any good?
I have read that Milorganite is good to put down in mid-August, but I would rather use what i have, if it is Ok.
Also about how long is the shelf life of open bags of Fertilizer?

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andy10917
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Re: School me on Slow Release Fertilizer

Post by andy10917 » August 9th, 2020, 9:58 am

Like most things, it depends...

Do you plan to do the Fall Nitrogen Regimen this Fall (have you read it?)? If you do, that involves getting a using fast-release fertilizer. Using slow-release just before it is a bit problematic in that we don't know when the slow-release is done releasing Nitrogen. So, when can we make the switch?

You can do what you want (it's your lawn), but with your decision, you take on the responsibility for figuring out the downstream decisions.

Open bags of fertilizer can last quite a while, but in humid environments may clump/harden, rendering them impossible to put into a spreader. Putting them in one of those Rubbermaid storage tubs is often good at preventing that from occurring.

mvftw
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Re: School me on Slow Release Fertilizer

Post by mvftw » August 9th, 2020, 10:05 am

I did read your post and I thought it meant to use a slow release, because you said that Milorganite is good to use and that is a slow release, or so I thought...

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andy10917
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Re: School me on Slow Release Fertilizer

Post by andy10917 » August 9th, 2020, 10:20 am

I have used Milorganite personally by the hundreds of bags, and know very well how long it takes to complete its cycle. The Fall Nitrogen Regimen is a rather intensive program, and it does not do as well with the use of slow-release urea fertilizers - you just can't get enough applications in to achieve the desired outcome.

The best way to do the entire program is to do a single half-rate or full-rate natural/organic fertilizer like Milorganite or grains just after August 15th, and start the Fall Nitrogen Regimen with fast-release Urea right after Labor Day.

Notice what I wrote yesterday in the "August: The Transition Month" thread:
the August 15 date looks good for gently waking the lawn with a light natural/organic fertilizer (no, Urea doesn't count).

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Re: School me on Slow Release Fertilizer

Post by mobiledynamics » August 9th, 2020, 10:55 am

Can one spoon feed or blitz new blades. Thinking about the over-seed. Or leave it alone for 2020 to let it focus on -roots-


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Re: School me on Slow Release Fertilizer

Post by MorpheusPA » August 9th, 2020, 11:10 am

mvftw wrote:
August 9th, 2020, 9:25 am
I have read from this forum that Mid-August is a good time for Slow Release Fertilizer.
I have 2 Lesco Fertilizer's:
32-0-10 +2% iron 21.6% slowly available urea nitrogen
25-0-6 +5% iron 11.25% slowly available urea nitrogen
My math would say that 32-0-10 is a better slow release.
But are they any good?
I have read that Milorganite is good to put down in mid-August, but I would rather use what i have, if it is Ok.
Also about how long is the shelf life of open bags of Fertilizer?
If 32% N has 22% slow N, then there's 78% (100-22) fast N. So 0.78*32 = 25-0-10 is the final number for fast release. (the potassium particles are not coated)
If 25% N has 11% slow N then there's 89% (100-11) fast N. So 0.89*25 = 22-0-6 is the final number for fast release.

The remainder is slow release, so the 32-0-10 has 7-0-0 slow release.
25-0-6 has 3-0-0 slow release.

Neither is good for August application as the nitrogen levels are too high at a time when the lawn wants a very light mid-afternoon snack of a small vegetable plate and perhaps a light fruit juice.

If those are your only options, skip the August application. It's not strictly necessary, just helpful. If you really want to put something down now, and can get to the store, pick up some Milorganite or any other grain-based feed.

These amounts of slow release are fine for the September feeding, however, so you can certainly use them at that point. And August is chugging along, so you can apply this around Labor Day. We can't say how long the slow release will last, so these would be once a season options. Don't use either one again within a...let's say four month period unless the bag specifically states that the nitrogen is released completely within a shorter period. The longest I've heard of significant nitrogen being released is about four months (Vigoro Super Green, which I use as my winterizer as I don't experience dormancy in winter).

The shelf life of open fertilizer is indefinite unless it gets wet. If you fold the bag over, or twist it shut, and it still flows, it should be good forever. Most fertilizers are urea-based, which will require some bacterial action in the soil to become active (it's minor and fast, and only takes a day or two). That won't happen even if they get wet, so the re-formed crystals can be broken apart if they get wet and dry out.

Other fertilizers are chemical and don't change form if they get wet. Again, just break them apart. However, these tend to turn to concrete and are more difficult to break apart.

In both cases, flowing them through the spreader will be a problem, so you can hand-spread very, very carefully, or use them in the garden, or discard them per bag instructions or your local ordinances. I usually use them in the gardens--they work fine, after all.

mvftw
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Re: School me on Slow Release Fertilizer

Post by mvftw » August 9th, 2020, 2:58 pm

I also have a bag of Screaming Green 16-2-3
Total Nitrogen (N)........................... 16.0%
3.0% ammoniacal nitrogen
10.6% urea nitrogen*
2.4% water insoluble nitrogen
7.25% slowly available urea nitrogen from sulfur coated urea.
2.40% slowly available water insoluble nitrogen from poultry manure and biosolids.

Healthy Start 3-4-3
2.8% Slow

Would either of these be good for Mid-August feed?

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