Posted: 27/03/2013 at 18:32
You ned to tie the main stems to the arch so you can see the structure and stop it all flapping around in strong winds. Use garden twine, not wires, and tie stems loosely with a figure of 8 looping round the frame and then crossing before looping round the stems. This allows room for growth and a bit of movement but keeps it all stable.
I use this stuff - I think it's called Flexi-tie. It's a stretchy plasic which has some give in it to allow for stem growth. It's a dark brown which 'disappears' visually, and doesn't rot like garden twine. Re-usable too!