Thank you all for your input and suggestions, I think that I will go
with seed, plug plants are expensive compared to a packet of seeds :-)
kate

I presume you intend native wildflowers?

In which case, try to check the source of the seed. Some packs of
'native' wildflower seeds actually originate from outside the UK. These
seeds, while the same species as the UK natives are often genetically
distinct. Using such seeds risks diluting the true, distinct UK native
gene pool. Not at all clear what the long term consequences could be but
generally genetic diversity is a good thing and diluting distinct
genetic populations is probably a bad thing.

For example, the UK varieties are probably prefered by UK insects and
more resistant to UK pests and diseases.

Yes indeed I do intend going for natives and thank you for that advice
and information.

kate