Cornfield Annuals on Clay
I'm trying to plan an area for wildflowers, and my partner prefers the idea of the cornfield annuals rather than a mini meadow. We have clay soil so my first question is, will they succeed on clay soil or is it too damp for them?
I've found the following seed mix on a highly recommended website, and am interested in it because it has more varieties of native flowers than the standard 5:
The mix is:
30% Corn Cockle
5% Corn Chamomile
15% Corn Marigold
10% Common Poppy
1% Corn Buttercup
10% Night-Flowering Catchfly
It's £9.50 per 100g which is more expensive than somewhere like crocus.co.uk, but it's got more varieties so I'm guessing it's very good value still.
My second question is, is this something I need to sow every year or do they generally self seed in following years?
My final question is, as the cornfield annuals don't include grasses are we missing out on lots of beneficial things for insects? Is there a particular type of perennial grass I could buy to plant nearby that would balance this out?
Thanks for any help,