Answer: Your Virginia Creeper (Parthenocissus quinquefolia) is a vigorously growing vining plant. As such, the vines will naturally grow up, no matter how often you try to coax them into growing in a horizontal direction. (It's a genetic thing... plant hormones responding to gravity and light.) Eventually, side shoots will develop from the main vines and these will be happy growing sideways, for a time, anyway. You can encourage the development of these side shoots by pinching out the tips of the main vines.
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