I've seen then grow VERY tall, Mr. Toad. Mine was a gift from a GW friend, and it took three years to take off. Once it did, it grew fairly quickly - probably 10 feet. Then a tornado took it out, but before that it was beautiful. A neighbor has one on his wall and it has been there 20 years and is two and a half stories tall (it is on his roof too) and spans the entire back of the bungalow, so it grows fairly tall. It blooms for almost two weeks and then it is finished for the season.

thanks, so much

mr toad