Posted: 04/07/2014 at 13:47
Caz, You can do a couple of things to renovate your flattened lawn. A good lawn food, well watered in if it doesn't rain, will feed the grass and get it growing well again, which may be enough.
If that's not enough, then do part or all of the traditional lawn overhaul - more usual in spring or autumn but not impossible in summer, with sufficient care. (Just make sure you don't apply grass seed too soon after a weed-killing lawn food: check the instructions on the lawn food container.)
Soften the existing lawn by soaking it. A good summer storm will do the world of good; otherwise - if you can spare the water - soak it with a hosepipe or watering-can etc. (Use the bathwater, washing-up water etc etc. if you want to save tapwater.)
Then spike the lawn all over with a fork to open up the soil, which will make the ground much spongier-feeling.
Level it off, using extra topsoil to fill any dents etc, then top-dress the whole thing. If you need to reseed it or thicken the grass, use grass seed mixed into the mixture of sifted soil/sharp sand (to help drainage). Brush it into the holes with a yard broom etc. Then water gently but regularly to get the seed growing.