Hops, how much can it grow?

I have started growing hops in Seattle 3 years ago and built a 8ft tall trellis system that I early found to be too short for my hops to grow. I added a horizontal wire last year for my Hallertauer to expand and it took it very well. This year I added the same thing for my other 4 plants, US goldings and Horizon and all have taken the 8ft vertical + 20ft horizontal wire and are still going.
I wonder how high would it grow before nature tells it that it is time to flower and stop growing.

it differs from species and area. the highes point on my setup is 20' the hops there hit the 20' and kept going. i lowered everything and ran the 5' it had dangling back down itself. it turened around and cleared the top again. im guessing my 1st hops plant(4yrold) has about 35' of growth b4 it started kicking sidearms. while others barely got past the 15' mark b4 they stopped.

My 3rd year Cascades are over 30 feet without the benefit of warm weather or much sun this year. Centennials 15feet and Magnums were chopped by lawn mowing dudes.

samc said:

...Magnums were chopped by lawn mowing dudes.

Click to expand...

Who were, in turn, chopped down by angry homebrewer?