how far apart do I plant the vines?

(Manitoba, Canada)

I'd like to plant Virginia Creeper to spread over some gabion rock cages we have along our lake front property. The soil is a clay/sand mix and the length of the cage is 213 feet long. Do I have to plant multiple vines and if so, how far apart do I need to place them?

Doug says that planting the vines every 8 feet give or take will fill in fairly quickly.