Posted: 13/10/2013 at 11:44
For a rosa rugosa that's a light trim - by midsummer it'll be twice the size and three times as glorious. I'd have cut it back by double that.
What you're missing is probably the green of the leaves, but rosa is deciduous, it won't have leaves on in the winter. I promise you, it'll be fine.
Great for wildlife too - a million times better than a boring Leylandii.
Hang some birdfeeders from the twigs and you'll be able to watch the small garden birds popping in and out of the hedge all winter, safe from any marauding sparrowhawks. Fantastic!