Our flats have a shared rear 250 square foot garden. Nobody did anything with it for years and it fell into pretty bad shape.

I have managed to restore about two thirds of it as (uneven and patchy) lawn with some flower beds. The rear third of it, however, is a series of 2 foot bumps and is a mixture of rubble, soil, weeds, etc. I am slowly digging it over and so far have dug up about 3 tons of soil which I have then finely sifted into large piles.

My plan is to spread this over the existing lawn, thereby evening out the bumps in the existing lawn. If I was to put about an inch of this sieved soil all over the lawn, will the grass that is there at the moment grow through ?