1 pound per thousand square feet in all cases. A bit less is OK as well.

Is it 1 pound per thousand square feet for the entire growing season or per application?

Thank You

Per app, 3 to 5 apps per season (May, September, October, November).

August might fit in if you're applying organically.

The numbers actually range from 0.7 to a nominal 1.0 pounds N per thousand, and even a bit lower is fine in May when the grass isn't feeding heavily.

Good to know, thanks morph

Hi,

How does this plan for 2021 look to you?

My yard is approximately 10,000 sq ft.

May 15th to 31st // Soil Temperature approximately 60F

Lesco 24-0-11

15,000 sq ft bag

I'll use approximately 42lbs of the 50lbs in the bag to get 1lb of nitrogen in this application.

Apply Halts Crabgrass and Grass Weed Control at the bag rate.

June 1st

Apply Grubex at the bag rate. Had grubs in 2020.

August 1st

Purely Organic 10-0-2

5,000 sq ft bag

I'll apply 4 bags to get 1lb of nitrogen in this application.

(Cheaper than Milorganite, I am going to give it a try)

September 1st

Purely Organic 10-0-2

5,000 sq ft bag

I'll apply 4 bags to get 1lb of nitrogen in this application.

Apply Jonathan Green's Mag-I-Cal at the bag rate if needed; will check ph.

Can apply at any time.

October 1st

Lesco 24-0-11

15,000 sq ft bag

I'll use approximately 42lbs of the 50lbs in the bag to get 1lb of nitrogen in this application.

End of November (when soil temperature gets below 45F)

Scott's Turf Builder Winterguard 32-0-10

15,000 sq ft bag

I'll use approximately 31lbs of the 37.5lbs in the bag to get 1lb of nitrogen in this application.

Thanks for your opinions and recommendations

A couple things--you'll benefit more from organic in May when it won't kick the grass, so I might be inclined to add more there. Move the date to May 5th to May 15th (soil temps really don't matter, you're applying it up top) and apply another app then. If you'd rather not, synthetic is fine, but I'd target 0.7 pounds of N on May 25th.

You can continue organically feeding right up to October, but that's optional and you can also use Lesco if you want. Either-or is just fine. The August feeding has to be organic, though, as you indicated yours would be.

Plus GrubEx should be applied in early to mid-May to give it time to work in. It has to be active when the grubs initially hatch, which will be right around September first. If the weather is dry over summer, that may not happen.

The November target isn't by soil temp, but when top growth stops. My current soil temp is 58 degrees, but top growth is slowing in reduced sunlight. I could technically drop right now as we're close enough, but I'll wait for the next set of rainy weather and call it close enough. This is not an exact science and my lawn's growth never really stops anyway, even in February.

Hi Morph,

I am confused; are you suggesting an organic application between May 5th and the 15th?

Then followed by another organic application on May 25th?

For a total of 0.7 pounds of N in May.

Please clarify.

Thank you very much

Either an organic app between May 5th and May 15th or a synthetic app around May 25th.

If you go with a synthetic, target 0.7 pounds N on May 25th. (For the organic, the target N doesn't matter so much--it's organic).

Thanks You Morph

Years ago I was on a campaign to stop talking in terms of NPK for organic fertilizer. What really matters is the protein content. Why? Because organic fertilizer is food for the microbes which live in the soil. If you over feed with organics, what might happen is you will overpopulate the soil with beneficial microbes. It is the beneficial microbes which eventually create plant food.

I still use a target protein mass for the nitrogen equivalency as the grass wants a certain amount of food per year in terms of nitrogen molecules traded from the bacteria to the grass for carbohydrates from the roots.

Adding 2 pounds of soybean meal per thousand? The grass is...less than content and the bacteria aren't happy either. At 10, it's OK. At 15, it's happy. At 20, exceptionally happy and moving into overkill. At 30, it's thrilled, and you probably have a significant odor issue as it decays (it's not awful and goes away in a few days), but no issues in terms of burning or anything. There's a very wide window.

Other items vary; for cracked corn or corn meal, at 30 per thousand it's OK, 60 it's happy, and above about 100 you might experience some smell (although corn never smells like soy does) and you've also spent a lot of money.

Alfalfa should never be applied above 20 per thousand for other reasons and, if you overapply and it smells, it also smells like absolute death on a pogo stick. 20 is not sufficient to feed the lawn very much and you should also apply 10 per thousand of soy to round it out. Alfalfa is used to stimulate root growth. I use a light spray of kelp instead for the limited good either actually do (the kelp, at least, also supplies trace nutrients).

@gle2011: Morpheus is suggesting organics in early May because you really want it to kick in in late May. It takes about three weeks for the bulk of the organic fert to work. Inorganics work immediately so you can wait until the end of May. So it is an either/or, not both.

@dchall: I hadn't really thought about that. If you add too much inorganic nitrogen I'm thinking you can overdose because it is in the form of a salt, which can damage the grass. It's not strictly the nitrogen causing the problem. The nitrogen from organics is produced by bacteria/whatnot in the soil and so is available in a different form. So can you have an excess of this kind of nitrogen without harming the lawn? I think morpheus tried to OD his lawn on organics and couldn't do it, right?

Yep. 1,300 pounds of organics per thousand square feet in a single season. On a soil that already had a solid base of organics and a prepped set of bacteria, fungi, and healthy set of worms and insects that hadn't been destroyed by insecticides and so on. I moved more than seven tons of material into ten thousand square feet over seven months.

I did, I think, overdose myself slightly on Ibuprofin, and I certainly did wrench my knee. But the lawn kind of glowed green. I think it squeaked a bit as it grew.

Grand total organic nitrogen: 37 pounds per thousand square feet. Normal target nitrogen: 5-6 pounds.

Organic nitrogen does pass through the salt forms, but most usually spends its time bound within a bacteria's structure. When that dies, it gets released (and transformed to the salt form), and the plant gets a chance at it. Or, it can be traded to a plant's roots in exchange for a sugar molecule. Or a fungus may throw a nitrogen molecule away that it doesn't need as it decays a dead bacterial mat. And so on. The system is complicated.

Really, in a well-balanced system, your synthetic nitrogen will get sucked up by bacteria as well--that's why synthetic nitrogen gets processed as fast as it does. There's urease in the soil. But that's another story entirely, and why my lawn can handle, easily, the occasional blast of synthetics without even blinking. The bacterial mass is strong enough and healthy enough to simply suck up the nitrogen I add. Or the dogs add. There's simply no burned spots--ever.