I've personally found that any upright structures the spiders can build their webs between is all they need. Maybe it's just my area, but if there's a place to fit a web one shows up. I've even had them set-up webs from the ground to maple and hickory limbs 8 ft up.
I appreciate their service, and I've always loved spiders, but it gets a bit annoying constantly getting tangled up in their webs. They've even set-up residence among some string
lights I have over the back deck. I don't mind it but company I have over tends to be a bit uneasy about it lol.
Perhaps setting up some bamboo stakes randomly through the garden would work?