I would like to plant a vine to grow up a trellis I will install along one side of a 7 ft treehouse platform. It faces North so not much sun with lots of tree canopy as well. Fast growing would be good but also thick coverage and hardiness are a consideration. The side of the platform I will trellis is in the picture, under the rectangular front window. Any advice would be much appreciated.
I’m attaching a link to a list of climbing and twining perennial vines from the University of Illinois. I think Virginia Creeper (Parthenocissus quinquefolia) included in this list is a good choice for your location. This vine grows in full sun to shade locations and is drought tolerant. It’s fast growing and has wonderful fall colour. Another possibility if you do get some sun is Climbing Hydrangea (Hydrangea petiolaris) with attractive white lacecap flowers in early summer and attractive bark for winter interest. Climbing Hydrangea is initially slow growing but vigorous once established.
We are becoming increasing aware of the issues with invasive ornamental plants. These plants are still readily available in many garden centres. I noted English Ivy (Hedera helix) in this list which is considered invasive in Southern Ontario. I’m including a link to the Grow Me Instead guide produced by the Ontario Invasive Plant Council which lists common garden plants with invasive tendencies along with appropriate on-invasive alternatives.