I had a large Maple tree removed and the stump ground last fall, then removed as much of the mulch as possible. Now I want to plant grass seed. there are still wood chips in the area that is approx 8-10" below the surrounding area, and there is some solid wood from the roots that were not ground far enough. Would applying a composted cow manure then top soil be a good way to go? Should I layer it below the new topsoil or mix it into the topsoil? Any suggestions would be appreciated.
You can't rush the process of getting an even level surface with consistent soil quality, to make a good lawn. It will take two or three years for the ground to get to that state, unless you go for the "nuclear option" of ripping up the whole lawn, re-levelling the area, and reseeding or replanting.
If you don't want to do that, and you don't want a permanent "feature" where the tree used to be, then dig out all the wood chips that you can, fill the hole with soil from elsewhere in the garden, and use the area as a small flower bed for annual flowers or bulbs for a couple of years. Re-level the soil surface and add more soil as necessary every 6 or 12 months as the tree roots decay and affect the surface level.
Once you think the soil is stable, instead of reseeding the bare patch, consider the option of lifting some of the existing turf from an edge of the lawn and using that to patch the hole. That will ensure you have the same mixture of species, and mature grass plants, which will camouflage the "repair" better than new seed or turf.
Two ideas for you.
- Plant another tree there. You will have to move to one side a bit to get enough room to dig a hole for the tree. Dig the hole first. I may determine what size potted tree you get. If you put the tree on the street side of the old stump, it will make the stump location less obvious.
You can follow this up by initally using this area as a flower bed. Put in a grass barrier, and fill the area inside with, say, daffodills and lillies.
- Plant a Rock. Yeah, big boulder. Put a foot or so of flower bed at the base, and plant what you like.
That spot will never match the rest of your lawn. More lawn on your property does the value of your property no favors. Why not some plant bed with river rock, boulders, breath taking plants (think of Dinosaur Food; Gunnera!), an 'artesian' water feature (no standing water, recycled water, refills automatically, creates this 'stero sound of water falling'...cheap and smart water feature) with a definite delineated shape/outline as an island of interest in your sea of grass??
The best way to get more power visuals out of your landscape is to define the edges. To not stuff so much into the picture the picture comes across as chaotic.
Edging your lawn with a flat shovel, carving a little trench between lawn and plant beds is the best thing one can do to improve how their lawn...looks like a professional installed the lawn.
Doesn't matter the radius measurement for the curves in a lawn with curved edges...but that measurement does NOT change until the direction of the curve goes the opposite direction. Consistent radius, use a hose and a stake and string. Upside down spray paint your edges. Throw the old grass and soil on your plant beds...or throw the grass in your compost. The human eye sees the edges, no so much the body of the lawn. As long as the body of the lawn is uniform in color and texture and form...it will look like a professional job just needing proper maintenance to fix the body of the lawn.
The roots of that stump are left to decompose by themselves. They will eventually decompose in the next few years causing sunken areas in your lawn, probably enhancing some mushroom fairy ring...Think of a 'paisley' shape, bigger is always better than tenuous and whimpy. Don't forget adding ornamental grasses to add movement and interest...If you are interested ask another question and we can get into more personalized detail.
Note: Jerry, you do not have to improve any soil to have what you are imagining. Get at least 2" of COMPACTED soil over that area and plant sod. In 5 years there will be a big depression that is easy peasy to fill and raise and plant again. Don't do anything special for that area after initial watering, no fertilizer...after 1 1/2 weeks when the sod is rooted MOW ON HIGH. Fertilize with the rest of the lawn. Make sure the sod is rooted just by trying to pull it up. A rotary mower will suck up sod not rooted. Sod will root and be very happy over crushed gravel if maintained for that sort of lawn bed.