Q.Fence climbers
I’m in zone 4-5 in Illinois. I’d like to hide an ugly fence with a climbing flowering plant but I don’t want to have to cut it back year after year. I’d like for it to just grow and cover the fence.
Look into Clematis virginiana, aka Virgin's bower. (avoid the invasive sweet autumn clematis, Clematis ternifolia). Other climbers, like climbing hydrangea, need pruning to keep in check once it has reached the size you desire. If allowed to grow on, they can become a nice groundcover. Here is a run down on common vines. I must mention that English ivy is horribly invasive and will gladly take over your property, trees and all if not kept in check. http://extension.illinois.edu/vines/perennials.cfm