How stump grinding works in Perth
A stump grinder uses a spinning cutting wheel to chew the stump and the surface roots down below ground level. What's left is a hole full of woody chips mixed with soil, and the deeper roots, which rot away slowly. Digging a stump out whole is rarer on suburban blocks because it means a much bigger hole.
Across coastal Perth, much of the ground is sand over limestone, the country tuarts grow in. Sand is easy for a grinder, but limestone close to the surface can stop the wheel short and send stone flying, which is one reason arborists set an exclusion zone before they start. Up in the hills, jarrah grows on rises of clay, sandy loam and gravelly laterite, which is harder going.
Before stump grinding starts in Perth
Find out what's buried there. Before You Dig Australia takes enquiries at byda.com.au, and Safe Work Australia's tree work guide says to check for services around a stump if grinding will go deeper than 200mm. BYDA plans don't show private pipes and cables, like irrigation or power to a shed, so tell the arborist about anything you've had put in. Keep kids and pets well away while the machine runs.
Stump grinding in Perth: what's local
Borer-zone wood
The polyphagous shot-hole borer quarantine covers the Perth metro area. In the Management Zone, untreated wood can't leave unless it's chipped to 2.5 cm or smaller, and machinery has to be cleaned before it goes. Ask how any big chunks of stump will be handled.
A stump that came from a sick tree
If the tree died with small round holes, frass or staining on the bark, report it to DPIRD before the stump is ground. City of Swan says not to remove or dispose of a suspected infested tree until DPIRD has advised.
Dieback in the soil
Phytophthora dieback is a root disease that moves with soil, and people shifting infested soil spread it faster than anything else. Over 40 per cent of native plant species in the south-west are susceptible, banksias and eucalypts included, so ask for a clean machine, especially near bushland.
A stump from a protected tree
If the tree was regulated under your council's tree policy, the removal approval may come with conditions. Read them before the stump goes, in case they cover replanting where it stood. Our WA permits page explains the council patchwork.
Questions to ask about stump grinding in Perth
- How far below ground the stump and surface roots will be ground
- Who's lodging the Before You Dig enquiry, and when
- What happens to the grindings: left in the hole, spread, or taken away
- Where any wood is going, given the borer quarantine
- Whether the machine is cleaned before it arrives and before it leaves
- Access: gate width, steps, retaining walls or a tight side path
- Proof of public liability insurance
After the stump is gone
Grindings are mostly wood, so they sink as they rot. Many people top the hole up with clean soil before laying turf or planting. If you'd rather not move soil around, ask the arborist to take the grindings away instead.
Fungi often fruit on old stumps and roots, which is a reason some people grind out stumps they'd otherwise ignore. Some eucalypts also shoot again from a low stump, so if green shoots appear after a tree comes down, an arborist can tell you whether grinding is the cleanest fix. For the longer version, see removing a tree stump.
Stump grinding in Perth: what you can do yourself
You can
- Lodge the BYDA enquiry yourself, through the website or app
- Mark irrigation lines, garden lights and anything else you've buried
- Clear pots, rocks and toys from around the stump
- Top up the hole and replant once the grindings settle
Leave to an arborist
- Running the grinder, which throws chips and stones at speed
- Stumps against fences, walls, slabs or pipes
- Any stump from a tree you suspect had the borer
- Big root plates left after a storm
Hiring an arborist for stump grinding in Perth
Lodge the BYDA enquiry the day you decide to grind, so the plans are back before the arborist comes. Then ask two Perth questions in the same call: how the wood is being handled under the borer quarantine, and whether the machine gets cleaned between jobs. A clear answer to both tells you a lot about who you're dealing with.