Core aeration (renovation)
Pull cores to relieve compaction so air, water and new seed reach the roots.
- When
- In order, while the lawn is being made
- For
- Any lawn
- Needs
- aerator
- Rule
- reno-aerate · Hessayon; RHS
Pull cores to relieve compaction so air, water and new seed reach the roots.
Why core, not spike
In a renovation the aim is to change the soil, not just poke holes in it. A core aerator pulls out plugs of soil, typically 1–2 cm (½–¾ in) wide and 7–10 cm (3–4 in) long, which relieves compaction and leaves open holes that seed and topdressing can fill.
How
- Do it right after scarifying, on moist but not wet soil.
- Make two passes in different directions for good coverage; aim for holes every 5–10 cm.
- Hire a powered core aerator for anything bigger than a small lawn; manual hollow-tine forks are slow but work on small areas.
- Mark sprinkler heads, cables and shallow pipes before you start.
The cores
Leave them to dry for a day, then break them up by raking, dragging a mat or mowing over them. The soil they contain helps fill the holes and level small dips.
Next: overseed the thin areas straight away, while the holes are open.
Do this first
Comes next
Sources
- D.G. Hessayon — The Lawn Experthessayon
- Royal Horticultural Society — lawn guidancerhs