What is left in the ground once a stump has been ground out?
A shallow pit of chips and soil, down to the depth agreed on the estimate. Below it sit the remains of the root collar, and running out from that in every direction are the lateral roots, which nobody grinds unless asked. That is the normal result of stump grinding in Hot Springs, and almost everything the spot does over the following year comes from those buried roots.
The heap raked back into the hole is not all wood. On the hillsides here the cutter wheel throws whatever the stump grew around, so the grindings come out mixed with soil, grit and flakes of shale.
The laterals are the part people forget. A big oak or pine spreads its roots wide and shallow, often well past where its branches reached, and the grinder only takes the wood near the trunk. The rest stays put and rots slowly in place.
Why does the ground sink where the stump used to be?
The chips and the roots under them are decaying, and as they shrink the heap goes flat and then turns into a dip. A big hardwood leaves far more wood underground than a small pine, so its spot keeps settling longer. There is no fixed calendar for it.
On a sloped yard, like the ones that climb off Park Avenue and Whittington, the first hard rain after a grind usually carries loose grindings to the low side of the spot, and a fan of chips ends up in the grass or the bed below. Rake it back. Topping the dip with soil works best once most of the settling is done, not the week of the grind, or the new soil sinks along with everything under it.
Will grass grow over ground-up stump?
Not well, straight into raw grindings. Wood chips mixed into soil pull nitrogen out of it while they decay, a standard warning in university extension advice on planting after a stump, and a heap of chips dries out fast on a south-facing slope. The usual fix is to pull most of the chips out of the hole and lay topsoil over the spot before seeding or sodding.
That matters more in Hot Springs than in a deep-soil town. The native soil on most of these lots is a thin layer over rock, so the few inches of topsoil laid over the old stump spot are most of what the new grass will root in.
The Garland County office of the University of Arkansas extension service names Bermuda, zoysia, St. Augustine and centipede as the warm-season grasses popular in Arkansas, and its guidance on sod says laying it in spring or early summer, while those grasses are actively growing, gives the fastest rooting. A stump ground in the fall can get its topsoil, settle through the winter, and take sod when the yard greens up.
Whether the chips stay in the hole or get hauled off is a line on the estimate, settled at the walk.
What are the mushrooms coming up where the stump was?
Fungi feeding on the old tree’s buried roots. The mushrooms are the fruiting part of the fungi doing the decay, and they tend to pop up after a rain, over the spot and along the line of a big root. They mean the roots are rotting the way they should, and the grass around them is not sick.
The University of Arkansas extension service answered this question for a reader with mushrooms around an old stump, and its answer was that short of digging up the stump and all the roots around it there is not much more to do. On rocky ground that dig is not worth it for mushrooms. Mow them down, and do not let a dog or a child eat one.
Mushrooms ringing a tree that is still standing are another matter. Some decay fungi work on living roots, and that tree should be looked at.
What about the big roots still running across the lawn?
On thin soil over rock, oak, sweetgum and pine roots stay near the surface, and some ride on top of it. A ground stump can leave ridges running yards out across the grass. What happens to each one depends on whose root it is and how deep it sits, and that gets sorted out at the walk.
- A surface root from the tree that came down, the one the mower deck catches every week. It is dead now, and it can be chased out along its run with the grinder, priced as its own line.
- A deeper root that runs under the grass instead of across it. That one is left to rot with the rest, and the settling it causes later is a shallow line rather than a hole.
- A root belonging to a tree still standing, the neighbor’s oak or the next pine over. It is not the old tree’s root at all, and grinding it wounds a live tree, sometimes one on the other side of a property line. It stays.
- Green shoots coming up from a root out in the lawn. That is a sprouting problem, covered in why a Hot Springs stump keeps sprouting.
Digging roots out by hand is the job that breaks shovels on these hillsides. Burning out what is left is off the table too, since open burning is restricted much of the year, as the guide to where brush goes under a Garland County burn ban explains.
Can I plant a new tree where the stump was ground?
Usually a short step to one side of it. A young tree set a few feet off the old spot goes into native soil, while the pit itself is rotting chips and dead roots that keep settling under a root ball. Planting in the exact spot takes a deeper grind with the chips hauled out, which is decided at the walk and is how stump removal that leaves room to replant gets priced.
On a lot that lost a pine, the City of Hot Springs urban forestry program publishes a list called Trees in the Urban Landscape, and it is a sensible place to start. Its special trees include bur oak, post oak and tulip poplar. It also lists American sycamore, bald cypress and eastern redbud, with crape myrtle and possumhaw among the small landscape trees. A tall shade tree wants room away from the house and the lines overhead. A small one fits the gap a pine left beside a bed.
Timing comes from the extension service too. Its horticulture answers put the best time to plant a tree in Arkansas at late October through November, with the dormant season running November through February. A stump ground in early fall leaves time to get a nursery tree in beside it the same season. One ground in July means waiting for November.