When is the best time of year to seed grass?
Getting the ground ready for seeding takes quite a long time, it needs raking and treading down several times to get it level and settled, it’s not an overnight job! Also I agree about planning the landscaping first, but it’s best to get all this done before putting in the seed, not just planned, as otherwise you will be walking over the site before it’s strong enough to stand it. Yes, in the Uk either Spring or Autumn is good, when it’s warm enough for good germination but there’s the likelihood of enough rain to help the seeds along. But had you thought of laying turf? Same preparation needed, but an almost instant result, much less chancy than seeding and easier to maintain very soon after you put it down. Not too much more expensive, and you can choose a suitable grade for the sort of lawn you need and its situation. Any spare bits of turf are good in the compost heap as well.