We are having an excavator come and rip out our back yard to make it level and finally have grass growing where pine trees once stood. The excavator is recommending that we mulch the old lawn and put it back into the ground, underneath our new sod and irrigation system. I can understand the organic material aspect of it, but wouldn't that just encourage the crab grass to come back? Also, with the old pine needles, wouldn't that add too much acid and kill the new sod? I am confused. Also a little weirded out because our wonderful dog likes to eat socks and other unmentionables, wouldn't that also end up under our new lawn? GOTTA love home improvement!
I would till in the old lawn, which will provide some nourishment for the new sod. I wouldn't focus so much on the old weeds you are tilling in, more so focus on keeping your grass healthy, regular fertilizing, proper watering, and aerating. Crabgrass like to grow in undisturbed soil, a lawn is a great example, aerating can help cut down on that. Keeping your lawn healthy and thick, (occasional overseeding if necessary) will prevent the weeds from growing. Good luck :)
No, you need to put seed or sod down on black soil, 6 inches minimum. It would be best to scoop out all of that mulch and fill the hole with soil. The mulch will rot and decay, and you'll be left with a dip in the ground which will be unsightly. Also the water will drain through the soil and into the mulch more quickly if you don't remove the mulch. Stump grinders usually offer to remove the mulch and fill the hole with soil for an additional price but they hate bothering with soil and usually won't do it unless you bring it up. :rolleyes: Anyway, you need at least 6 of black soil on top of any mulch and it would be much better to get rid of the mulch completely and fill with soil. At that, it would be best to let the soil settle for a few weeks, bring in more soil to level it off, and then sod or seed.
Old pine needles will not make your soil acid, so do not fear that. Crab grass is an annual that grows from seed each year, it germinates in response to sunlight. So unless you are going to remove the top layer of soil, burying the grab grass is a good idea. Mulching under the new sod is not a good idea, unless the new sod will be watered consistently each day until established. It would be better to add good top soil instead of mulch before laying down the sod.
I know rubber mulch is supposed to be very good for the ground - it reduces the weed growth and protects the soil from the hot rays of the sun. I think you may like to look into it - It gave my garden a fresh new start! Hope it helps you. Good Luck!
