Last season I planted a potato vine because I loved the purple flowers
it promised to provide. Well, it got HUGE trellised to the fence,
shooting up 10 feet to resemble a tree, but never put out a single
flower. I can only hope that it'll put on a better display this
season. I'm wondering whether cutting it back might stimulate some
flower production, or whether it'd be advisable in any case. And if
so, how far back should it be pruned?