It depends on how big they were when you receive them, the length of your growing season and the care they get. You do not have to feed them much fertilizer as they are not heavy feeders like roses. They can get 8' tall though. I will see if others in Z5 will comment on how fast theirs got to 4' (and from what starting size); it should be interesting. Most Macs that I have reach 3-4' in two years from a 5g pot but I have a slower growing Glowing Embers that is still about 2-3'.

My Limelight was 3-4 ft. the 2nd year. I started with a very small (Bluestone) plant.

Wow, talk about explosive growth Donna!

Both of mine were fast growers as well. I think they both hit three feet by thier second year and I started them as 6 inch tall one gallon plants.

Do you trim them in late march or early April? I planted two Limelights in August last year, from ~ 2 Gallon containers. I have not done any trimming yet prior to the winter.

Thanks
Vivian

I like pruning them in early spring - March-April in Michigan. I enjoy the flower heads in the winter.

Here is a link that might be useful: The Plant Hunter

Thanks Duncan for the information and the link. It has so much good information.