as promised here are the photos of how i make my cloches.
i use lengths of tubing from B&Q plumbing dept.
then i drive canes into the corners of my beds, and intermittently inbetween for longer tunnels
carefully bend the tubing and slide onto the canes
do this as many times as needs be. you can also adjust the height depending on how far down you slide the tubes.
then tie canes to the arches. you can also use string instead, though string tends to sag after a while and canes can rip the fleece/enviromesh.
cover with fleece/mesh/plastic. tuck in the sides or weight them down with bricks etc.
here one i made earlier (always wanted to say that!! :D