Help! What is doing this to my lawn?

personal.philip.oakley

Hi,

I'm very much a novice gardener and am looking for some advice as to what may be causing the divots in the lawn - photos attached.

It started as only a few so I thought it was our son smacking the grass with a cricket bat etc at first, but more seem to appearing. The damage is being increased overnight.

Any help would be greatly appreciated as I'm at a loss to know what's causing it and where to start with preventing it.

Thanks in advance,
Phil 

Obelixx

Looks to me like you have an infestation of leather jackets and the resulting damage is form bigger critters hunting and feeding.   They are the larvae of crane flies and not usually a problem unless your lawn is in poor health like yours as they eat the roots and weaken it further - https://www.rhs.org.uk/advice/profile?pid=651 

First thing to do is buy or hire a scarifier which is like a small electric lawnmower but with prongs isntead of blades.    Run it all over your lawn in both directions and compost all the thatch it pulls up.   Your gras swill look worse for a while but it will get better.

Next step is to take a large garden fork and poke it into the grass as deeply as you can and then wiggle it back and forth to widen the holes.   Work backwards so you don't close them up with your weight and make the holes every few inches/10 to 15cms.   Then pour on some dry, sharp sand - not builders' - and brush it over and into those holes so they stay open and thus improve drainage and aeration so the grass roots can grow more strongly.

Finally, raise the blades on your mower to their maximum height fo rthe last few cuts this autumn and the first few next spring.   Longer grass feeds better roots and you then get a virtuous circle of stronger plants.   If there are loads of bare patches, you can gently rake the soil loose and then sow some fresh seed while it is still warm enough and the rains will help it germinate and grow.

Next April you can sow more for any remaining bare patches.