Hi, how much a plant grows in a year is dependant on too many things to give a definitive answer, all I can tell you is that they grow to about 12ft high with a spread of 5ft or more, you may find that the new shoots you get next year grow taller than the ones you have this year, Derek.

Agree with Derek. Basically it will grow faster with more water and feed and slower if you do not.

Also it may not grow quite as quickly this year as next - it may take a little time to establish and put new roots down