When you are thinking about a new lawn or renewing a lawn, there are really only two options – Grass Seed & Ready grown grass in the form of turf. There is a 3rd option – green plastic, but that’s the devil’s work and, for most people (who buy that to solve their problem) that is a big costly mistake. But that’s for another time.
Grass – You need to clear the ground, make it more or less level or a level as possible, remove any stones & weeds etc on the surface, firm the ground down and then – tip – water the area well and leave it for 3 days. The soil will settle, and any remaining weed seeds will show their ugly head. You’ll more than likely find some more stone too. Once all that is removed, you can throw on your seed down. Some might want to give the ground a light rake either before, after, or both. This should be a very light scattering of seed. In a week’s time you can add some more seed and even give some more after another week. This produces the best results for cost at the end, but meantime don’t over water – naturally if it rains you have no options there – but your enemy is the dry. Ideally, you want the ground to remain just damp.
Turf – Similar clearance and first water of the soil then lay the turf, there is a lot of rubbish said about how to lay turf, butt it up or leave a slight space but never more than the thickness of your finger. The idea of leaving a real gap, probably come about to save on cost. If you have 12 rows of one foot wide turf with a gap of an inch (20 mm) then you are saving a whole row of turf to buy.
But here’s a reason you might not use turf – Turf is grown on massive fields and often delivered miles away, it’s very unlikely the soil that grass is grown in, and the same soil it’s still growing in delivered to you, is the same type as the soil you will be putting is on in your garden. As soil dries and get wet it moves, if the soil under your turf moves around more than the soil the grass is grown on what you will see is clumps of grass after about 18 months. This may well end up look worse than the lawn you replaced. The grass hasn’t had time to get deeply rooted and your nice square of turf is pulled apart in the wet and then as it dries the soil pushes up into these gaps leaving a sort of pixilated lawn. You just wasted your time and money. So be warned.