Easy to forage (though get permission) and giving amazing shapes to arrangements. 

Foliage with the tiniest palest pink of flowers.

Honesty flowers in the summer, then throws out seed pods. You can then peel the outer part, collect the seeds for next year and reveals pearly insides!

Late summer flowering, they keep pushing out blooms as the weather cools. Then, dry them to keep using them for all year colour!

One of my favourites - easy to grow, you can use fresh for fountains texture, or miscanthus dries into such a fantastic fluff.

Spiky little seed heads, fantastic for biodiversity and the animals, but also dried can give so much interest to your arrangements.