Last year, we had a large area we were transitioning from 100% grass/weeds to rougly 75% shrubs and perennials and 25% grass.
-Sheet mulched (Mow grass as low as possible. Lay overlapping cardboard, wet it, then top with compost, soil) the entire area late July last year.
-Planted shrubs and perennials in the September.
-Put down winter or "dormant" grass seed in late October.
The grass seed just started sprouting a weeks ago. First time trying it, we'll see how it comes in.
But essentially no weeds. I'm convinced sheet mulching is the most effective at turning grass/weeds into new plantable space, with minimal weed regrowth.
In 6 warm seasons we've turned about 2/3 of the half acre lot from grass into plantable soil. Lot of work but better for us, pollinators, environment, and property value.