Use discarded, old or reject black poly pipe in hooped sections. A 38 mm diameter pipe is ideal, although heavier pipe could be used if a tall screen is planned. If you decide to use poly, don't set your supports up until some growth is available for training. Then curve the pipe to the height you want and bury the other end. A 50 mm or 75 mm pipe will support large arches but bury more deeply and use steel pipe stiffeners fitted internally into the first 2 m from each end.
Bottlebrushes are available in many different forms and colours.
For screening purposes, the cream flowered C. salignus sold under the name Willow bottlebrush, is a good choice. White and pink colour forms are also available in this species. C. salignus will reach 7 m under ideal conditions, and can be pruned to a tree form later in life. It tends to adopt a relatively vertical profile, but if the top branches begin to overhang the base and retention of the lower foliage is required, saw off the larger overhanging branches at their bases. Restrict heavy pruning of this nature to the winter months.