How to aerate a lawn, and when it is worth doing
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How to aerate a lawn, and when it is worth doing
Aerating sounds like a job for somebody with a shed full of gear, and it really isn't, because all you're doing is putting holes in the ground so that water and fertiliser can get down to the roots instead of sitting on a hard crust at the top. If your lawn has gone patchy and hard underfoot and nothing you feed it seems to make any difference, this is usually the thing that's missing.
How to tell if your lawn actually needs it
The clearest sign is water. If rain or the sprinkler pools on top and takes a while to soak in, or it runs off down the slope instead of going in, the soil underneath has compacted and the water has nowhere to go. The other test is pushing a screwdriver into the lawn, because if you have to lean on it to get it in a few centimetres, the roots are having exactly the same trouble.
Compaction comes from use, so the parts of the lawn that need it most are the ones that get walked on, which is usually the track between the back door and the shed or wherever a trailer gets parked on the grass. The rest of the lawn is often perfectly fine.
The other thing worth checking is thatch, which is the layer of dead runners and old clippings that builds up at the base of the grass. A bit of it is normal, and once it gets thick enough that water sits on top of it rather than going through, it does the same job as compacted soil.
When to do it
Aerate while the grass is growing, because the holes heal over and the lawn fills back in, and doing it while the lawn is dormant just leaves you with a lot of holes and no recovery. Most lawns around here are warm season types like kikuyu or buffalo, and they grow hardest from late spring through summer, so that's the window. Cool season grasses like rye and fescue do their growing at the other end of the year and are better aerated in autumn. If you're not sure which one you've got, bring a piece of it in and we'll have a look.
How to do it
- Water the lawn the day before, because damp soil takes a fork and dry soil fights you the whole way.
- Mow it a bit shorter than usual so you can see where you have already been.
- Go over it with a garden fork, pushing it in as deep as it will comfortably go and rocking it back slightly to open the hole up. A coring aerator pulls plugs out instead, which works better on badly compacted ground because it takes soil away rather than pushing it sideways.
- Concentrate on the tracks and the worn patches rather than trying to do the whole lawn evenly, because that is where the problem actually is.
- Feed it and water it in afterwards, while the holes are open and the fertiliser can get down to where it is useful.
If the ground is badly compacted and it's heavy clay, getting gypsum through it after aerating is worth more than another feed, because gypsum works on the structure of the soil rather than the nutrients in it, and there's not much point feeding a lawn that can't get water down to its roots anyway.
The bit nobody tells you
Aerating on its own doesn't do a great deal. The holes are just how you get something useful into the root zone, so the value is in what you do straight afterwards, which is feeding it and topdressing it. Aerate and then walk away, and the lawn will look about the same in a fortnight.
It isn't a hard job. It's just an unfamiliar one, and those are two different problems.
Shop related products
- Neutrog Blade Runner Lawn Fertiliser 15KG. Pelletised lawn feed to put on while the holes are still open.
- Neutrog Sudden Impact for Lawns 10kg. The faster acting one if the lawn needs pulling around in a hurry.
- Brunnings Green Up Lawn Food 5kg. A smaller bag for a smaller lawn.
- Brunnings Kikuyu Lawn Seed 1KG. For oversowing the bare patches once the ground is open.
Did you know we also stock gypsum in 10kg and 20kg bags, garden lime in 10kg and a soil pH test kit in store. They're not on the website, so give us a ring on (08) 8536 4333 to check what's on the shelf.
The rest of the lawn gear is in the garden centre, and if you want a hand working out whether your lawn needs aerating or just a decent feed, come in and ask.
Read next
- Topdressing, the quickest way to bring a tired lawn back
- What makes regular mowing the foundation of good lawn care
- How to stop fertiliser and water running off your lawn
I'm still the sort of gardener who aerates the track to the shed and calls the whole lawn done.
Candeece
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