Hedgerow planting

I planted a native hedgerow a couple of months ago (a whole mix of things such as hawthorn and hazel) and despite the mulch I’ve put around it I’m having a real problem with weeds coming up to choke the young hedge plants (3 ft saplings) so I’d really like to  plant a wild flower seed mix around it to cover the ground and deter the more aggressive weeds. It’s in full sun most of the day. 

Would planting wild flowers there cause a problem for the hedgerow plants? Any advice you can give would be really appreciated

Jess