HOPS, HOPS, HOPS!! If your aren't looking for an evergreen vine (not sure if there are any for your zone), you can't beat hops for fast and complete coverage, and bonus you can harvest and freeze the cones for brewing! Double check the variety for your zone, look into a Canuck Homebrewers Forum somewhere, I am sure those geeks will rant and rave about certain varieties for your zone. I get our hops from "Freshops" in Oregon. Cheap to put in, too, just order the rhizomes and plant away, they'll go from bare root to 13-20 ft in a few months. More expensive choice may be Virginia Creeper for your zone, or Clematis, although the Clematis may not fill in as much as you want.
Even if you don't brew, remember that there are people out there in the homebrewing world who will buy your hops! (Depending on the variety!)
Virginia Creeper and climbing roses would be two that might work.
Perennial Clematis sounds good. Very pretty.http://www.allaboutrosegardening.com/Clematis-Vines.htmlAnd maybe Perennial sweet peas – lathyrus latifoliushttp://www.pfaf.org/database/plants.php?Lathyrus+latifoliushttp://joenesgarden.wordpress.com/2009/06/01/goops-day-–-part-deux/I love the smell of sweet peas.
I'd suggest the scourge of the South, cudzu (it never dies back!) but I doubt it would survive your winters.I like the hops suggestion though - maybe I could convince my dad to take up homebrewing again :)
There are some ivys that would completely cover (picture old buildings) but you have to be careful as sometimes they get out of control and you CAN"T kill them. I have a friend who's husband has been growing his own hops for several years here for his home brew, but has to buy more for the quantity he brews. I don't remember what they look like, but something that covers and produces would be a double bonus!!
I like Virginia creeper (the leaves provide beautiful fall color too) and wild grapes (and so do the birds!)If you're interested in either of those, let me know and I'll dig some up from my yard and ship them to you (they're pretty easy to grow).
Honeysuckle and wild jasmine are soooo yummy.
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