Wisteria, Wildflowers and Weeds

I went out for a few hours today. The wisteria at Shugborough Hall was calling and it didn't disappoint. We enjoyed our picnic of onion bhaji baguettes and savoured the midweek quiet of a National Trust property. The mansion wasn't open but we were very happy walking in the vast grounds. As well as wisteria there were bluebells, cow parsley, forget-me-nots, alliums, azaleas, late daffodils, tulips and green alkanet. 
To be honest, I had to look up the name of this plant. I thought it was a weed and many would agree but it looked stunning in the walled garden's borders amongst forget-me-nots and mountain cornflowers. 
Most of the grass at Shugborough was left unmown and just tidied up at the edges. The buttercups and dandelions looked beautiful in the long grass especially in the sunshine. Parts of my city's public spaces are being left unmown. I like these little steps towards rewilding. Do you like the naturalised look? When is a weed not a weed?