On 15/01/2014 20:16, stuart noble wrote:

My son's lawn has a dip in the middle. The whole area is probably 60 ft
x 20 ft and the centre is about 3" lower than the edges. I thought of
trying a quick fix by leveling with topsoil/sand/seed and hoping the
existing grass will grow through it. Is that a realistic expectation?

If you top dress the low spots about an inch at a time over three years
you won't need much if any seed. You will likely need a lot of sharp
sand and topsoil though 25kg goes nowhere. If it is deeper as I had with
a big tree root extracted and you use new grass seed expect to see a
different coloured patch of grass there almost forever!

I read a long discussion about it on Gardenweb, so I know about sand
types etc, but what works in the southern USA might not be successful in
SE England. With a toddler charging about, doing a proper job isn't an
option for the foreseeable future .

Any advice welcome

If you don't add too much at once grass it pretty good at growing
through and re-establishing itself. You might want to attack the low
spot with a hollow tined fork to improve drainage first. Get a really
tough one as the ones in sheds are pretty useless and break easily.

--
Regards,
Martin Brown