Ground sinks where a tree was because the wood left below, roots, ground-out chips or a whole buried stump, shrinks as it rots and the soil above drops into the space. Fix a shallow dip by scraping out loose chips and filling with topsoil in firmed layers, mounded slightly high, but treat a hole that keeps opening, or one under paving, as a sign of a bigger piece of buried wood that has to come out.
Three reasons the ground drops
Every sinking spot comes down to wood turning into nothing. The first kind is the hollow over a ground stump, where the grindings and the stub of wood below them decay and pack down. The second is a narrow groove running out from where the tree stood, which is a big root rotting underneath. The third is the one that catches people out: a whole stump, or a pile of them, buried during building or clearing years ago. That one can sit quietly for a long time and then open up after heavy rain. The shape of the dip usually tells you which of the three you have.
Reading the shape of the dip
A round, shallow bowl right where a stump was is almost always the grind settling. A long trough running away from it follows a root. A hole well away from any tree you remember, deeper than it is wide, or one that opens suddenly, needs more care. It may be a buried stump, but it could be a broken pipe, a collapsing septic line or an old dry well. Do not reach or step into it. Keep children and pets away, mark it, and think about what runs under that part of the yard. NC811 points out that privately owned lines are left unmarked, so your own records matter here.
Filling a small dip properly
For a settling grind spot, rake out the loose chips first. Iowa State University Extension says the shavings ideally come out before new topsoil goes in, since they make it hard for turf to grow, and advises filling the hole with topsoil. Put the soil in a few inches at a time and firm each layer with your foot or a tamper. Water it, let it drain, and top it up again. Finish a little above the lawn, because it will keep dropping a bit for a season or two. Then seed or lay sod. Each top-up after that should be thin, so the grass grows through it.
Why one fill is rarely the last
The wood under the spot keeps rotting for years, and the ground follows it down a little at a time. The big roots near the old trunk last longest, so a slight dip can come back after the first fill looked perfect. That is normal and small: a bucket of soil, raked in, a pinch of seed. What is not normal is a spot that drops by inches again and again, or that turns soft and spongy underfoot. That points to a large mass of wood below the surface, and topping it up will never catch up with it. The fix for that is to dig the wood out.
Buried stumps on building lots
When land is cleared for houses, stumps have to go somewhere, and in the past some were buried on site. North Carolina now treats a burial area for land clearing debris on a property as a small landfill. For on-site areas of half an acre or less, state law calls for a survey recorded with the county register of deeds, a disclosure before the land is sold or leased, and no buildings within 50 feet. So a deed search may show one on your lot. If your yard keeps sinking in a newer subdivision, ask the builder what was done with the stumps. In South Carolina, ask your county.
When it keeps sinking: dig it out
A spot that will not stay filled needs opening up. A machine digs down to find the wood, lifts out the stump, root mass or buried debris, and the hole is backfilled with soil in compacted layers and topped with topsoil. That is a job for an excavator or a loader rather than a shovel, and it leaves the ground sound enough to mow, plant or build on. It is the same work as full stump removal, only the stump is already underground. If you are digging it yourself, the excavator dig-out guide covers the backfill steps.
Sinking under a patio, walk or drive
Soil settling under grass is a nuisance. Under a hard surface it cracks the slab, tips pavers and leaves a dip that holds water. If a patio or path was built over a ground stump, or over roots that have since rotted, the surface has to come up, the wood has to come out, and the base has to be rebuilt and compacted before the surface goes back. The lesson for new work is simple: if something hard is going where a tree stood, take the root ball out first. For leveling a whole area after removal, see leveling the yard after stump removal.
Common Questions
What should I fill a stump hole with?
Topsoil, not wood chips. Rake the loose grindings out first, as Iowa State University Extension advises, then fill with topsoil a few inches at a time, firming each layer. Leave it slightly mounded so it settles to level. For a deep hole under something built, use compacted fill as the base, with topsoil only where grass or plants will grow.
How long will the ground keep sinking where a tree was taken out?
Usually for a few seasons, a little less each year. The chips and small roots rot first, and the large roots near the old trunk take longest. A thin top-up of soil after each settling is enough under a lawn. A spot that keeps dropping by inches has a bigger piece of buried wood under it.
Can a sudden hole in the yard be caused by rotted tree roots?
It can, especially where a large stump or a pile of stumps was buried long ago. It could also be a broken pipe, a failing septic line or an old well. Keep people and pets away, do not step in it, and think about what lines run there before anyone starts digging to find out.
What to Do Next
If a stump spot keeps sinking, or you want a stump gone without leaving a hole to nurse, call (828) 574-4474. A photo of the spot, how big it is and what is planned there is enough to start, and the quote is free.