How do you grind a stump?
You grind a stump by lowering a rotating cutting disc fitted with carbide teeth across the wood in 25–50mm passes until it sits 150–300mm below ground level. A typical 30cm stump takes 15–30 minutes, plus 10 minutes of cleanup, raking chips back into the void.
The pattern is simple: position the wheel at the top edge of the stump, lower it slowly, then sweep left and right across the cut face. As the wheel chews down through the wood you drop another 25–50mm and repeat. A small operator-walked machine clears 30cm of stump in three or four sweeps; a larger ride-on grinder does it in one.
The cut wood comes out as chips — not sawdust. Chips fly forwards and sideways, which is why a barrier or chip-guard is set up before the wheel touches the wood. The chips collect in a cone around the stump and are raked back into the hole at the end of the job.
What equipment is needed?
You need a petrol or tracked stump grinder (5HP–35HP), a Greenteeth or Sandvik cutting wheel, full PPE (helmet, visor, ear defenders, steel-toe boots, gloves), a rake and shovel, and barriers or boards to protect surrounding lawn from flying chips up to 5 metres away.
Hire-shop machines are usually in the 13HP–25HP range and weigh 150–300kg. They walk through a standard 90cm garden gate but struggle with anything steeper than a 15-degree slope. Professional outfits run 35HP–60HP tracked units with remote control — these chew through a 60cm oak stump in 20 minutes that would take a hire machine half a day.
The cutting teeth matter more than the engine size. Greenteeth carbide pockets are the industry standard because each tooth can be rotated through four cutting positions before replacement, lasting 15–25 stumps per face. Cheap fixed teeth blunt fast on grit and gravel buried around the root collar.
How deep should you grind?
Grind 150mm below ground for a lawn re-turf, and 250–300mm if you plan to plant a new tree or lay a hard surface. The British Standard for re-planting is 300mm. Anything shallower than 100mm risks the stump regrowing or causing settlement.
Most homeowners ask for "below ground level" without specifying a number. The honest answer is: it depends on what goes on top. Turf and topsoil need 150mm clearance so the grass roots have soil rather than wood fragments to grow into. A new tree needs 250–300mm so the root ball can sit in clean soil, not on top of a decaying stump.
Patios, sheds and driveways need 300mm minimum because as the residual wood and roots decay over 5–10 years the ground above sinks. A patio laid on shallow-ground stump fill will tilt within three years. The depth question is also one of the big drivers of the final stump grinding cost — a 300mm grind takes roughly 50% longer than 150mm on the same stump.
What about the wood chips?
The grinder produces 3–8 wheelbarrows of wood chips per stump. Standard practice is to rake them back into the hole as backfill, top with topsoil, and re-seed. Removing chips off site adds £25 to £50 in disposal time. Chips are also useful as path or border mulch.
Fresh stump chips are not the same as bagged bark mulch. They are coarser, often mixed with soil and small root fragments, and they steal nitrogen from the surrounding soil as they break down. Use them on paths, around mature shrubs, or in compost — not directly around seedlings or new lawn unless you top-dress with nitrogen.
If you plan to re-turf within a fortnight, take the chips off site or pile them somewhere they can rot down for six months. Otherwise back-filling is the tidiest option: the chips fill the void, settle within a month, and the lawn over the top stays level. Send us a photo and a postcode for a fixed price and we will tell you which option suits your stump — get a free quote here.
