I don't know if you'd count this as a hedge as such but it's certainly working for me. I collect Buddlejas and have been sticking non flowering small branches in the ground in autumn down the side of the low fence in my back garden. Some I've grown as small "trees" by stripping off the lower branches as they appear and some I've left as bushy shrubs. The leaves mostly drop in winter but as I'm not sitting out in the garden then, or using it as another room to entertain in, I don't mind the lack of privacy then and the many bees and butterflies visiting in the summer more than make up for the bareness in winter. And the flowers are just beautiful I am very excited that the RHS has brought out a new one this summer - it looks like it's pink and butterscotch - can't wait until they're on sale ! One is going to the right of the front door and will be grown as a small tree.

I like the idea of collecting rosehips and planting them and will definitely try that this year. Thanks for the tip.