Lawn or turf over a ground stump
Rake the excess mulch out of the crater and spread it on the garden, then add your own quality soil, mound it 50–100mm above the surrounding level, and firm it down with your heel or a light roller.
Then seed or lay turf as normal. Expect some settling over the first few months — top it up once with more soil and it'll be invisible.
- Remove most of the wood chip, don't just level it
- Add your own quality soil, not the grindings
- Mound slightly to allow for settling
- Add a little slow-release nitrogen fertiliser to offset drawdown
Shrubs and garden beds
Small shrubs, flaxes, grasses and perennials go in fine as long as their root ball sits in real soil rather than chip. Dig the planting hole wider than usual, fill around the plant with a compost/soil mix, and keep the mulch on the surface where it belongs.
Planting a new tree in the same hole
This is the one case where standard grinding isn't enough. A new tree needs a large volume of real soil and no decaying timber competing for nitrogen and hosting fungal decay. If you want a replacement tree in exactly the same position, ask for full removal of the stump and root plate, then fill the hole with good soil yourself before planting.
If you can shift the new tree a metre or two to one side, standard grinding is fine and you save the excavation cost.
How long should you wait?
Lawn and small plants: straight away, once you've added your own soil. A new tree in the same hole after grinding only: leave it 12 months or more, or better, have the stump properly removed instead.
Auckland's wet winters speed decay up, so grindings left in a garden bed break down noticeably within a season.
Common questions
- Can I plant grass where a stump was ground?
- Yes. Rake out the excess wood chip, leave the area tidy, add your own soil mounded slightly above grade, firm it down and seed or turf. Add a little nitrogen fertiliser to offset the drawdown from any remaining chip.
- Can I plant a new tree where the old one was?
- Not over standard grinding. A new tree needs real soil and no decaying root plate, so either have the stump fully removed and fill the hole with soil yourself, or plant the new tree a metre or two to the side.
- Are stump grindings good mulch?
- They're excellent surface mulch around established trees and shrubs and they're free — just don't dig them into planting holes, and keep them off the crowns of small plants.