How stump grinding works

A stump grinder is a toothed wheel on an arm that sweeps across the stump, chewing it and the top of the main roots into chips, working down to 300–400 mm below the surface. That's deep enough to lay turf, plant a garden bed or pave over, and it takes about half an hour to an hour for a typical backyard stump.

Before we start

We check for pipes, cables and irrigation near the stump, and ask you about anything you know is buried there. Stormwater and sewer lines often run past old trees, and irrigation lines are rarely where anyone remembers.

The grind

The machine comes in through the side access (most suburban paths are fine), is positioned at the stump and works across it in passes, lowering each time. The main roots are followed out as far as they are a problem, for example where they run under a path. Chips are thrown into the hole and around the stump.

Afterwards

• Mulch or take away. The grindings can be left in the hole, spread as mulch or removed. Tell us which you want.
• Settling. Back-filled grindings settle as they break down. If you're turfing straight away, top up with soil first.
• Regrowth. Most eucalypts and ornamental trees won't regrow once the stump is ground this deep. A few species, such as camphor laurel, privet and some wattles, can sucker from roots left in the ground, and we'll tell you if yours is one of them.
• Approval. None needed: once a tree has been legally removed, grinding its stump doesn't need council approval.

Grinding compared with digging out

Digging out a big stump means excavating a hole wider than the root plate, often with a machine, and it disturbs everything around it. Grinding works from the top down and only removes the stump and the top of the main roots, so paths, fences and garden beds nearby are left alone. The roots left deeper in the soil break down over the following years.