Soil

The meadow is made in the soil

Wildflowers don't want rich soil. Fertility grows grass, and grass smothers flowers. The poorer the ground, the better the mix.

What to do

scrape      strip the top of fertile topsoil
starve      cut and remove, never leave clippings
suppress    sow yellow rattle — it weakens grass
wait        let the seed bank wake up

Yellow rattle

The one species that does the weeding for you. It parasitises grass roots and opens the sward, so your flowers get a gap instead of a fight.