The message
from "[H]omer" contains these words:

Hi,

I'm going to be sowing a wildflower meadow in a steep verge at the back of
our garden, approx 40ft long X 14ft high with a flat top about 6ft wide.

Meadow ecologies are maintained either by grazing animals, or by
people imitating grazing by cutting and removing all the topgrowth.
Unless this is done, nature will take its course...coarse plants with
big leaves (like dock) shade out smaller ones, exactly what you're
seeing.

You need to think very carefully about how you are going to regularly
mow a steep slope 14ft high. Unless you have a way to do it, you'll
never make it into a wildflower meadow.

Your climate is neither as wet, nor as mild, as Ireland's. If you go
ahead, your best source of advice and seed is local. I recommend Jupiter
plants which are in East Scotland; specialist suppliers for such
projects. You'll find them with a websearch.

Janet.