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I've got a 50' x 5' wide section in the back of the yard that will not grow grass. At first I thought it was because the two trees in the back of the yard. I pruned the trees and still no grass. I dug up the dirt and see a sandy layer about 5" down. I tested this soil:

  • pH: 7.5, Alkaline
  • Nitrate: low
  • Phosphorus: high
  • Potassium: high

The backyard is Bermuda grass. By circumstance, some men dug up that area of the yard with a tractor and pulled up a bunch of limestone. I seeded Bermuda, poured about 1" of new dirt on it but it did not grow.

What can I do to make the grass grow?

Back of yardenter image description here

Dirt: enter image description here

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    Kudos, P.Brian!! You got a soil test!! Send pictures, perhaps a little scaled drawing of the area and trees, vegetation, relation to house? 5 X 50 feet sounds like an old driveway. Lawns love alkaline, but maybe not 7.5. Sand layer? Limestone layer? Pictures!! None of these things are a deal breaker for a lawn. Are you seeding or sodding? Nitrogen will have to be increased and we need to know more about your soil to understand what HIGH means for phosphorus and potassium. It is a good thing or a not so good thing. Explain in detail about your other grasses and have done to prepare. – stormy Aug 16 '16 at 2:20
  • @stormy - Ok, I'll update this question tomorrow. Too dark to get any pictures now. I tried seeding. Did not see a limestone layer, just sand. The limestone is spread out. A lot came up because they dug a 30" hole about 50 feet long. Then they left a lot of this rock above ground. I picked most of it up. – P.Brian.Mackey Aug 16 '16 at 2:22
  • No problem! Take a shovel and cut into the soil to take a picture of the profile. How deep is this sand layer, what is beneath it? I am very interested as I've seen grass grow on gravel (sod, however). Did you bring in topsoil? How did you water? Did you add fertilizers? More information, I've spent decades learning all about this creature called a lawn. – stormy Aug 16 '16 at 2:28
  • Stop lying, Jack Spirko is a soil masochist, and his yard looks amazing compared to the "concrete slab" he started with. things will grow there, but it will be very hard at first. – black thumb Aug 19 '16 at 4:30
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I seeded bermuda. Poured about 1" of new dirt on it. Did not grow.

I'm no expert, but from what I have read, grass seeds must be planted no deeper than 1/4".

  • Yeah, as I understand it, you don't even need to bury it. Just scatter/spread it evenly, put straw (or peat or whatever) on top (not a lot), and keep it watered. – Shule Aug 21 '16 at 1:47
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I'm pretty sure the answer is that your pH is too high (that depends on who you ask) and especially that your nitrogen is too low (I think most will agree on this). If you have high potassium and low nitrogen that will probably inhibit germination and growth.

People generally lower the pH with sulfur, but that can take a lot of time and it isn't always the best solution according to some. I prefer mixing/tilling peat moss in with the soil to lower the pH, since it adds organic matter, too, and is bulky. I'm not into lawns much, but I'm thinking ammonium sulfate, urea and such might be good for the nitrogen as might different nitrate fertilizers (but calcium nitrate would be a bad idea since your calcium seems to be high from the lime, and calcium nitrate is said to kill soil microbes).

You might also try growing inoculated clover in with your grass (if you don't mind extra bees in your grass), as it should help to increase nitrogen. Or, you could do only clover.

Grass is supposed to love nitrogen.

I must admit that I don't know for sure that these measures will increase germination rates, although I believe the organic matter from the peat moss should help considerably, especially if the soil drains too fast. Composted manure may help too. People or sites might tell you not to use a high nitrogen fertilizer, but because your other soil nutrients are high, you need to balance them with extra nitrogen.

In my area, people usually put straw or hay over new grass seed. It helps to keep the soil moist and probably eventually supplies natural nutrients. Straw is high in nitrogen. It is said to protect the seeds from being blown away or eaten by birds. I don't know if you did that, but it might be a good idea.

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