Sowing wildflower seed doesn't often give the hoped-for results. For a more reliable show we think the Achilleas (yarrow) and Anthemis (chamomile/maguerite) look wonderful together.
These are perennial plants that will come back year after year (and will have an evergreen centre year-round). They are bee-friendly, grow well in poor, dry soils (but aren't too picky) and do best in sun. Anthemis are £5.99 each; Achilleas are available in £3.29 and £4.50 pot sizes in a range of colours.
Really go to town and combine with plants from our cut flower range!