Wood Chip and Grinding Spoil Removal in Gallatin

Run the Wood Chip Volume Before You Decide

Solid wood turned into grindings roughly doubles in volume, because you are adding air and soil to it. A 30-inch stump taken to 10 inches below grade, flare included, produces somewhere around one to one and a half cubic yards loose. Call it eight to twelve wheelbarrow loads. It mounds two to three feet over the hole, because the hole is nowhere near big enough to hold what came out of it.

Two of those in one visit and you have a pickup bed and a half sitting in the yard. A row of eight Leyland cypress stumps, each individually small, throws more total spoil than one big oak does.

That number is the whole decision, and it is why we quote both options in advance. People say to leave it while picturing a bag of mulch, and mean it right up until they are standing over the pile at four in the afternoon.

Grinding Spoil Is Not Mulch

What comes out of the hole is wood mixed with a substantial fraction of soil, grit and, in this county, limestone fragments. That changes how it behaves in a yard. It does not compost evenly the way clean arborist chips do, it packs down instead of staying loose, and it hides small rock that will find a mower blade the first time you cut over a spot where it was spread thin.

There is also a nitrogen effect worth understanding rather than fearing. Microbes breaking down fresh wood pull nitrogen out of the immediate contact zone, so grass seeded directly into a chip layer comes up thin and pale while that is happening. Spread on top of an established bed as surface mulch, the same material causes no trouble.

The rule that covers almost every case: spoil on top of soil is fine, seed on top of spoil is not.

Walnut Grindings Have a Chemistry Problem

Black walnut is common in Gallatin's older yards and along the creek bottoms, and its wood, roots and hulls carry juglone. Tomatoes and peppers are the classic casualties. Azalea, rhododendron and blueberry are also sensitive, and so are a fair number of the perennials people plant in the bed where the tree used to stand.

Juglone does break down over a couple of months in well-aerated compost, but a two-foot pile of walnut grindings sitting on a vegetable garden is the opposite of well aerated. So when we grind a walnut, the spoil goes on the truck, or onto a path or a wooded edge well away from anything you intend to eat. It does not go into the raised bed, whatever the pile looks like on the day.

Nothing else we grind around here carries this issue. Hickory, oak, maple and cedar spoil are all chemically harmless to what grows nearby.

Backfill, Settling and Where a Pile Cannot Sit

If sod or seed is going down, backfill the hole with topsoil and let the spoil leave. Chips packed into the hole will settle, and they settle unevenly. Expect four to six inches of dish in the first season and more if the hole was deep, and expect it to appear right after the new grass has finally knitted together.

Where the pile sits matters too, and not only for looks. Gallatin runs a municipal stormwater program under its own adopted ordinance, and loose organic spoil left at a curb inlet, in a swale, or on a bank falling toward Town Creek or an Old Hickory Lake embayment is a discharge waiting on the next thunderstorm. We stage clear of drainage or we load out the same day.

Curbside is not the fallback either. Grinding spoil is not brush, and the city's collection program is not built to take it.

Sensible places for grinding spoil, and one bad one

• Surface mulch on an established shrub bed, kept off the trunks
• Filling a woodland path or a muddy gate approach
• A back corner pile left to break down over two or three seasons
• Spread thin across a rough area you do not mow closely
• Hauled off the same day when sod or seed is going down
• Never packed into the hole under new turf, because it dishes as it rots
• Never piled on a walnut job anywhere near a vegetable garden