By Paco
United Kingdom 
Hi - two years ago after having building work down I had a new lawn made using turf. On the second winter this was very lumpy and bumpy so got the firm back again this year to lift the turf, rotavate and re-seed. Lawn looks ok but when walking on it you can feel tiny hard bumps. Lifted a few and it’s not gravel etc but grass and hard soil. I can’t face changing it all again but don’t know what to do - scarify? aerate? At my wits end. Please help
Lynne
26 Aug, 2013
I would top dress with a sharp sand/fine compost mix which will settle through the grass blades, filling in any dips that way. Don't use a roller - it only compacts and firms, it won't take out the bumps, and you'll have a poor drainage and compaction problem then!
Perhaps a couple of weeks after you've top dressed you can do a little cosmetic surgery to remove the last little nodules. A thin slit with an old knife and a small operation. Recovery will be rapid.
The company should learn how to prepare properly!
26 Aug, 2013