@CurlyhairedAssassin
I've got a free packet of meadow mix seed from Gardener's World magazine. Should I be careful about any of these?
borage, lavender, oregano, vetch, tickseed, cornflower, corn marigold, larkspur, viper's bugloss, Californian poppy, flax, field poppy, zinnia, phacella?
Cornflower, corn marigold, california poppy, flax, field poppy, phacelia are all annuals. They may seed around a bit, but won't be difficult to uproot.
Borage and Vipers bugloss are in the forget-me-not family, some members of which can be thugs, but I don't think these two are.
Oregano is perennial and freely seeding. My mother used to complain about it, it's never worried me. Lavender is perennial but won't be a problem.
Vetch - depends on the vetch. Vicia sepia bush vetch, is very prolifically seeding and is perennial. Vicia sativa, common vetch, and Vicia cracca, tufted vetch, aren't a problem.
Tickseed I've no idea what that is and zinnia I've never grown. Ah - tickseed is Coreopsis. Never grown it.
Very interesting marketing if that was sold as a "meadow mix". The only one I'd expect to find in a meadow is the vetch. The rest are flowers of arable fields, needing clear soil for germination, or flowers of bare mountain sides.
At least they didn't label it "wildflowers" since 5 of those are not UK natives.