How Deep Does Stump Grinding Go, and Can You Plant There After
“How deep does stump grinding actually go” is really two different questions wearing the same sentence. The depth that suits a new lawn isn’t the depth you’d want if you’re planting a tree in the same spot.
Typical grinding depth
Machine size makes the biggest difference to how deep a grinder can reach. A smaller, pedestrian style grinder that can get through a standard gate typically reaches around 30cm below ground level. A larger tracked machine, where access allows it onto the property, can go deeper again, to around 40cm. Either way, the stump itself disappears well below the surface, with wood chips left behind rather than a hole.
What depth you need for turf or lawn
If the plan is turf, lawn, or general garden bed over the top, you don’t need anywhere near the maximum depth a machine can reach. Around 15 to 18cm of soil sitting above the ground is more than enough for grass roots to establish properly, which means a grind depth of around 20cm below ground level already gives a comfortable margin. Beyond that point, going deeper for a lawn isn’t buying you anything extra.
What depth you need to plant a tree in the same spot
Planting a new tree where the old one stood is a different question entirely. A young tree needs room for its own root system to spread out properly, so this is where you want as much depth as the machine can manage, not the shallower depth that’s fine for grass. There’s a practical reason for this beyond just physical space: wood chips left in the ground tie up nitrogen in the soil as they break down, which is exactly the wrong environment for a young tree trying to establish itself nearby. The deeper the old stump and its immediate root zone are grinded out, and the more of the chip fill that gets removed rather than left in place, the better the conditions for whatever you plant next.
Access affects depth too
The depth a machine can reach isn’t only about the model, it’s also about whether the bigger, deeper reaching machine can actually get to the stump in the first place. A stump behind a narrow gate or down a set of steps may only be reachable with a smaller machine that doesn’t grind as deep as a larger tracked one would on open ground. If deep grinding matters to your plans for the space, it’s worth mentioning the access situation upfront rather than assuming the deepest option is automatically available.
Why “just fill it in” isn’t the same as grinding deeper
It might seem like a shallow grind topped up with extra soil should give the same result as grinding deeper in the first place, but the wood left closer to the surface keeps breaking down and settling under the new soil, which is exactly the uneven ground and dips that turn up months later. Grinding to the depth the job actually needs, rather than compensating with more fill on top, is what avoids that problem altogether.
The short version
Laying turf over the spot: a moderate grind depth is genuinely enough, and there’s no benefit chasing maximum depth for grass alone. Planting a tree in the same hole: go as deep as the machine allows, and get as much of the chip fill out as practical before you plant.
If you’re not sure which situation you’re in, or whether your yard’s access even suits the bigger machine, that’s worth sorting out before the job rather than after.
Stump Boss grinds stumps big, small and hard to reach, from North Brisbane to the Sunshine Coast. Send a few photos for a quote and mention what you’re planning for the space afterwards.
Related reading: how to repair your lawn after stump grinding Service page: stump grinding
Stump Boss does stump grinding and lawn aeration from North Brisbane to the Sunshine Coast.