Amethyst Falls Wisteria and my Deck

[troiano]

Hello everyone, I am new to this forum. This past weekend, I completed construction of my deck and pergola. I went to my local nursery, looking for a vine to climb and cover my pergola. They recommended Wisteria, and sold me Amethyst Falls Wisteria. I bought 5 plants, 1 for each 4x6 support. Since planting them on sunday, Ive been reading up on them. While I read they are less invasive then their Asian counterparts, I'm begining to sense I have overplanted. I loved the vision (in my head) of 1 vine growing up each support, and forming a massive canope above. The way my deck is built, it keeps them away from my house, and pruning should keep them from reaching that far.

Is this too many plants? Will American Wisteria give me the canope cover Im looking for? There is a picture attached of the deck.

Thank you,
Jeff in Mt Juliet TN (zone6)