Fall is here, and it’s already taken its toll on my once-lush, green grass. But before the weather turns too chilly, October provides the perfect opportunity to repair damaged lawns and prepare them for the winter months ahead.
And one essential task is to aerate your lawn to prevent waterlogging and ensure key nutrients reach the soil. However, with constant drizzles and damp conditions expected throughout the fall season, is it okay to aerate a wet lawn?
I asked a lawn care expert to find out and get their top tips.
Can I aerate a wet lawn?
Generally, you can aerate a slightly damp lawn but not when it’s saturated with heavy rain — so it’s important to distinguish between the two.
“A simple rule is that damp is fine, soggy isn’t — if water is standing on the surface or the tines come out coated in sticky mud, wait a few days,” states Jonathan Davis, lawn care expert at Lawnsmith.
“Spring and fall are the best times to aerate partly because the soil is moist, which makes it easier to get the tines in, and showers can soak straight into the freshly aerated soil. What you don’t want is soil that’s so wet it smears. Then you’re not opening up the soil; you’re sealing it, and you still want air reaching the roots.”
Top tips for aerating a damp lawn
What's the best way to aerate a damp lawn in fall? While there are several ways to aerate your lawn, it’s important to choose the right tool in fall.
Typically, there are two types of aerators – spike and core aerators. Spike aerators literally have long spikes that puncture the ground as you pass over it, while core aerators pull up ‘cores’ of soil as they work, leaving them on the surface.
“If the ground is on the damp side, solid-tine spiking is the gentlest approach, and you can do it any time from March to November, but avoid very wet soil that smears,” advises Davis.
You’ll also need to know the right time to aerate your lawn and best practices. “Fall, from the end of September to mid-November, is ideal as the weather is getting wetter rather than drier,” suggests Davis. “If you’re using a hollow tine aerator, mow the lawn close beforehand as it makes the cores much easier to deal with.
“Cores should be left to dry in place. Then go over them with the mower with the box off, if the instructions allow. It puts the soil and nutrients back into the lawn and helps break down thatch. If you can’t do that, rake them up with the back of a flat rake, use them as top dressing, or add them to the compost heap.
Finally, finish with a good soak on compacted areas. After spiking or hollow tining a heavily compacted patch, run the sprinkler for 30 minutes, then leave it off for a day or two.
Also, look for telltale signs your lawn needs aerating, including patchy, yellow grass or water sitting on the surface after rainfall.
When not to aerate a wet lawn
Besides knowing when it's the right time to aerate wet soil, you should also know when to avoid it. This includes before incoming frost, which can freeze the aeration holes and harm the lawn.
“Don’t aerate very wet soil that smears, and don’t do it if frost is imminent because freezing soon after hollow tining will make the lawn heave up,” adds Davis.
“Don’t leave the cores on the lawn to disappear, as they won’t break down fully and you’ll end up with a bumpy surface. Finally, don’t expect aeration to fix everything. If your lawn is 20 years old or more and badly compacted, you may need to dig it over to at least 15cm and start again.”
For more top tips, check out how often you should aerate your lawn and how many passes are best.