Grinding gets rid of the stump. It does not get rid of the tree's whole root system, and nobody enjoys finding that out after they have laid the turf.
Most of the time it makes no practical difference. Sometimes it does. This is what stays in the ground, when it matters, and what can reasonably be done about it.
Grinding takes the stump and the roots near the surface down below ground level. The deeper and finer roots stay where they are and break down over time. That is fine for lawn and garden beds. It matters when you are building on the spot, when roots have already lifted something, or when the species suckers.
What is actually left down there
Picture what a mature tree has under the lawn. A thick flare of buttress roots around the base, larger structural roots running out from that, and then a wide mat of finer roots spreading much further than the canopy ever did.
A grinder deals with the first part and whatever it can safely reach around it. The rest stays put.
Where the tree does not sucker, the remaining roots gradually break down. How that happens depends on the species, the timber, the soil and how wet the spot stays. Large structural roots generally remain longer than fine roots.
Why it usually does not matter
If the plan for that patch of ground is turf, mulch, a garden bed or just a level lawn you can mow, leftover roots are rarely a problem. They sit there, they rot down, and the ground settles as they go.
The settling is the part worth knowing about. As buried material breaks down, the spot can sink over time and may need topping up.
When it does matter
There are four situations where leftover roots are worth dealing with properly rather than leaving to time.
You are building on the spot
Slabs, footings, retaining walls, driveways and pool surrounds do not want timber decaying underneath them. If a builder, engineer or certifier has given you a requirement, that requirement decides the work — not the stump. Get it in writing and quote the ground preparation against it.
Roots have already lifted something
Surface roots that have pushed up pavers, cracked a path, tilted garden edging or broken a section of concrete are a separate job from the stump. They can often be ground out where it is safe to reach them, but how far they run and what sits beside them decides how much is practical.
The species sends up suckers
Some trees respond to losing their trunk by pushing new shoots out of the remaining roots. You get a rash of little stems appearing through the lawn or the garden bed, sometimes metres from where the tree was.
Cutting new shoots at ground level is one way people manage suckering, but the response varies by species and the roots may need separate advice. Mention any new shoots when you ask about the stump.
You want to plant a replacement tree in the same hole
A spot full of chip and decaying root is not the ideal place to establish a new tree straight away. If you want a replacement in exactly the same position, say so before the grinding is done so the finish and the backfill can be planned around it.
What to do with the grindings
Grinding produces a surprising amount of material — a mix of wood chip and soil that ends up sitting in and around the hollow.
You have three ordinary options:
- Leave it as backfill and let it settle
- Take some out and top the hole up with soil
- Have the lot removed and the area filled properly
Which one suits depends on what is going on top. One thing worth knowing before you plant into it: fresh wood chip mixed through soil pulls nitrogen out as it breaks down, so seedlings and turf can struggle in it. If the spot is going straight to lawn or garden, it is usually better to remove the chip and bring in soil rather than plant into the grindings.
The written quote should say which of those three you are getting.
What is under the ground comes first
Roots and services share the same space. Water, gas, stormwater, communications and electrical services all run through suburban yards, and roots have a habit of growing along them.
Chasing roots away from the stump means cutting through ground you cannot see into. Their location needs to be checked before that work happens, and it can limit how far the grinding can reasonably be taken. Anywhere near a footpath, driveway, nature strip or meter is worth flagging when you ask for the quote.
Roots near pipes and paving
Two things people often ask about together, and they are different problems.
Roots in a sewer or stormwater line are a plumbing issue as much as a tree one. Removing the tree does not clear the line or repair pipe damage, so that work needs to be assessed separately.
Roots under paving are a surface problem. Grinding the accessible ones can relieve it, but if the paving has to come up anyway, doing the two jobs in the right order saves money. Tell us which is happening first.
Common questions
Do the roots keep growing after the stump is ground?
The old root system does not keep extending in the same way after the tree and stump are removed, but some species can send up new shoots from remaining roots. The response varies, so mention any suckers when you ask for advice.
How long do the roots take to break down?
It depends on the size, species, timber, soil and moisture. Large structural roots generally remain longer than fine roots, which is why building requirements need to be considered separately.
Can you take out all the roots?
Not with a grinder, and not really with anything on a normal suburban block. Grinding reaches the stump and the accessible surface roots. Getting more than that means excavation and disturbing a lot of ground.
Can I lay turf straight over a ground stump?
Often, once the chip has been dealt with and the level is right. Ask what the quote includes for the grindings and the finish, and expect to top the spot up as it settles.
Is root removal the same as stump removal?
No. Taking out the stump and root ball is a different job from grinding, and even that leaves the finer roots behind.
What to do next
Tell us what is going on that spot and send photos of the stump, the ground around it, any lifted paving and the way into the yard. That tells us whether it is a straightforward grind, whether the surface roots need chasing, and what finish the quote should allow for.
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