This is what the RHS say for Rosa rugosa 'Rubra 'As most shrub roses tend to flowers best on older stems, they only need a little light formative pruning. Hard pruning should be avoided unless absolutely necessary as it can often ruin the plants shape. The best time to prune is in late summer after they have finished flowering. While wearing tough gloves, remove dead, damaged, diseased or congested branches completely. If the centre of the shrub is becoming congested, remove one or two of the older stems to their base. If they have become too leggy, then you can often encourage new growth to form by cutting one or two stems back to within 10 - 15cm above ground level.
You can trim your Hornbeam now.