To grow grass where a stump was ground, dig most of the grindings out of the top several inches, refill with topsoil mounded slightly high, let it settle, and then seed or sod with the same grass as the lawn around it. Seed tall fescue from mid August into early fall, plant warm-season grasses such as bermuda or centipede in late spring, or patch with sod through the growing season.
Match the patch to the lawn first
A stump patch looks wrong for years if it is the wrong grass. Before buying anything, find out what you have. NC State Extension in Henderson County notes that the lawns of western North Carolina are largely tall fescue, a cool-season grass that stays green in winter. Lawns in the Upstate may be fescue or a warm-season grass such as bermuda, centipede, zoysia or St. Augustine, which go brown after frost. If the lawn browns in winter and greens up in May, it is warm-season. Pull a few runners and take them to your county Extension office if you are unsure. Then buy that grass and nothing else.
Seed or sod for a stump patch
Both work. Seed suits fescue lawns, because fescue grows from seed readily and the patch blends in by spring. Sod suits warm-season lawns and impatient people. It covers the patch on day one, and some grasses give you no choice: Clemson Extension lists centipede, common bermuda and zoysia among the warm-season grasses that can be seeded, while St. Augustine is started from plugs or sod. For a patch only a few feet across, a single piece of sod cut to fit is often simpler than seed. Ask for the same grass as your lawn.
Getting the soil right
Grass needs soil in its root zone, not wood. Dig the loose grindings out of the hollow until you reach firm soil or solid root, and set them aside for mulch. Refill with topsoil. On thin or clay ground, Clemson Extension suggests bringing in as much as three inches of it, with lime and fertilizer added as a soil test directs. Firm the fill with your boot, water it well, and let it sit for a few days or a good rain. Top up any drop. The surface should finish level with the lawn for seed, a little lower for sod.
Seeding the patch: dates and amounts
NC State Extension's fescue calendar sets the mountain seeding window at mid August to September 1, and the Piedmont window at September 1 through October 1, at about six pounds per thousand square feet. Henderson County's center adds that soil needs to be above sixty degrees for good germination. A stump patch three feet across is around seven square feet, so you need only a small handful. Spread it evenly, rake it in lightly, and press it down. For warm-season seed, Clemson targets the first two weeks of May. Clemson's advice is to water lightly a few times each day for around three weeks, so the seedbed never dries out.
Sodding the patch
Cut the sod to the shape of the patch with a sharp spade or an old knife, so its edges butt tightly against the lawn with no gaps. The soil underneath should sit about one sod thickness below the lawn, so the new piece finishes flush. Lay it, then press it down hard. Clemson Extension says to roll or tamp sod right after laying to remove air pockets, then water to a depth of four inches, keep the soil moist to that depth every day for the first week, and then water lightly until the roots grip. Tug a corner after a couple of weeks. If it resists, it has rooted.
Feed it for the wood still below
Even with the chips dug out, old roots and some wood remain under the patch, and wood ties up nitrogen as it decays. Clemson Extension explains that soil microbes need roughly twenty-four parts carbon to one part nitrogen, and that materials far richer in carbon than that make them tie nitrogen up, so less is left for plants. Wood is far richer in carbon. The sign is a patch that comes up fine and then pales to yellow-green. A light feeding of lawn fertilizer, timed for your grass type, usually brings it back. Your county Extension office can tell you the right product and timing for your lawn.
When the patch sinks later
It probably will, a little, as old roots rot. Small dips are fixed by topdressing. Clemson's topdressing guidance caps each layer at half an inch, spread while the grass is actively growing, using soil like your own worked down between the blades. Repeat a few weeks later if needed. For a deeper dip, cut and lift the sod, add soil beneath it, and lay it back. Leveling the yard after stump removal covers larger holes, and planting after stump grinding covers trees and beds.
Common Questions
Can I lay sod directly over stump grindings?
You can, but it seldom does well. Sod laid on chips dries out fast, pales as the wood ties up nitrogen, and sinks as the chips rot. Scoop out the loose chips, replace them with topsoil, give it time to drop, then lay the sod on soil about one sod thickness below the lawn.
How much grass seed do I need for a stump hole?
Very little. NC State Extension's rate for tall fescue is about six pounds per thousand square feet, so a patch three feet across needs only a small handful. Spread it evenly over the topsoil, rake it in lightly, press it down and keep the surface damp until it comes up.
When is the right time to seed fescue over a ground-out stump in the mountains?
Late summer. NC State Extension's dates are August 15 to September 1 in the mountains and the whole of September in the Piedmont. If the stump is ground in spring or summer, fill the hollow, let it settle and wait for that window.
What to Do Next
Planning grass for the spot? Mention it with your photos and the grindings can be piled or hauled, leaving the hollow ready for soil. Ring (828) 574-4474. How the grinding itself runs is on the stump grinding page.