Green Green Grass Of Home

Hi Hollow101 - before your Dad mows the lawn he should wait until the worm casts are dry enough to brush and spread around the lawn - this should stop them being squashed into the lawn and making patches. The other thing he could try (if he already doesn't) is to apply a lawn dressing in the spring or summer which includes some ammonium sulphate. Hope this helps.

Only a small proportion of the worms that are in our soil are casting worms. To use a wormkiller would kill all the worms!
There are wormkillers to be had on the professional market but I am not so sure about the amateur side.The worms will not cast throughout the season and I would recommend using a beesom when its dry to distribute the casts before mowing. This will act as a topdressing and along with the aeration performed by the worms, will be good for the sward!
I believe,worms, along with weeds enjoy alchaline conditions so using acidic fertilizers can help to lower the alchalinity and deter the worms. Sulphate of ammonia is an excellent fertilizer for fine turf but it's a bit too late in the season to be promoting lush growth. Sand topdressing can help as worms don't like the coarseness of the sand on there bodies. Some of the fungisides used by professionals have a secondary use in contolling worms to some degree but you would need to check at the Garden centre for amateur products. The problem can be disguised to some extent by raising the height of cut, and even using a rotary mower without rollers.

If all else fails, you could always dig the lawn up and fill it with fruit and veg! Lol