Plugs can be planted directly into areas of turf in order to establish a wildflower meadow. 

A crop such as oil-seed rape can be grown on the soil and harvested.  The crop takes nutrients out of the soil and removing the crop at flowering time ensures the nutrients do not return to the soil.  Soil that has low fertility is typically needed for a wildflower meadow

We can control weeds and vigorous grasses by introducing plants that are semi-parasitic.  Rhinanthus minor (pictured below) is often planted in wildflower meadows because it is semi-parasitic.