Why grind a stump
Cutting a tree down leaves a stump, and stumps cause problems. They are trip hazards in lawns, block mowers, get in the way of new paving or garden beds, and slowly rot. Rotting wood can attract termites, which are common in Perth's coastal sands. Some species also send up new shoots from the stump, so the tree keeps coming back.
Stump grinding is the usual fix. A machine with a toothed cutting wheel chews through the stump and the top of the root flare, turning it into a mix of wood chips and soil. It is quicker and far less disruptive than digging a stump out.
How grinding works
The grinder is positioned beside the stump and the spinning wheel is swept across the wood, taking off a layer at a time until the stump is below the surface. Surface roots running out from the stump can be followed and ground as well, if they are in the way of lawns or paving.
The operator checks the area first for anything that might be damaged, including irrigation lines, garden lighting cables, pipes, paving edges and windows that might catch flying chips. Screens are often set up to contain debris.
Sand makes a difference
Scarborough, Trigg and North Beach sit on pale coastal sand over limestone. That has some advantages: the ground is easy to work and drains quickly. It also has some quirks.
- Limestone close to the surface. Stumps can sit on or wrap around limestone, which limits how deep the grinder can go and can blunt cutting teeth. The contractor may grind to the rock and stop.
- Wide, shallow roots. Trees in sand often spread roots well out from the trunk. Grinding the main stump is straightforward, but chasing every surface root across a lawn takes extra time.
- Settling. Grindings and sand settle as the wood breaks down. Expect a slight dip that needs topping up after a few months.
Getting the machine in
Many Scarborough homes have narrow side gates, steps down to rear yards, retaining walls on sloping blocks near Trigg and North Beach, or access only through a garage. Compact grinders are designed for this, but tighter access can affect which machine is used and how long the job takes. When you enquire, mention the narrowest gap on the way to the stump and any steps.
What to do with the grindings
Grindings are a mixture of wood chip and soil. You can:
- leave them in the hole to settle and plant over later
- rake them out and use them as mulch on garden beds, once they have aged
- have them removed and the hole backfilled with clean sand or soil, ready for turf or paving
If the stump was from a diseased tree, or from a host species for the polyphagous shot-hole borer, ask the contractor about the right way to handle the material under current Department of Primary Industries and Regional Development rules.
Before you build
If the stump is in the way of a slab, pool, or driveway, tell the contractor. These projects often need deeper grinding and removal of major roots, so the builder is not left with organic material beneath new work. It can be worth getting your builder or engineer to confirm what depth they need.
For planning prices on single stumps and multiple stumps, see the cost guide. If the tree is still standing, start with the tree removal page.