Q.Planting Climbing Plants
I have ordered an arbor (84″) to place over the path leading from our front gate to our patio. Placement of the arbor will depend on the sun and trees in our yard. I have chosen to plant Nelly Moser clematis to climb this arbor and I would like to know: do I have to plant one either side of the arbor so they will eventually meet at the top, or should I just plant on one side of the arbor so it will grow up an over to the other side?

Certified GKH Gardening Expert
This is really up to you, though planting one on either side will speed up the coverage. For additional information on growing and caring for clematis vines, these articles will help: https://www.gardeningknowhow.com/ornamental/vines/clematis