My 2nd year Zeus, Galena and Centennial have all topped my 14' trellis. They haven't minded the weather at all, but I also have them in a very sunny spot and they're well fertilized/mulched.
If you're not seeing the growth you want, I would ask:
1) How many hours of direct, south sunlight do they receive? (for this you assume the sun in shining all day, not relative to cloudiness, just a gauge of how sunny your spot is under perfect conditions)
2) Have you fertilized them with a quality, preferably organic slow-release fertilizer?
3) Is the root zone competing with grass, weeds, other garden plants for nutrients in the vicinity? Grass in particular will choke out other plants' attempts to expand and grow underground.