hydrangea

Does this not depend on the variety? We have in a cold environment at least two obviously different hydrangeas that peaked at 4 ft. and 7 ft. high.

Don't really know but guessing 3-4 years.

I guess it depends on where you are. I've seen hydrangeas reach full height in 2 years, but my area has winter rains - with no snow, so they grow all year long.

There are many different kinds of hydrangeas. Ours are all about 5 years old and only the Oak Leaf Hydrangea attempt such heights. The mopheads and lacecaps are content well shy of 6 ft. The second year they were as tall as they ever got. Some grow new wood each year, some keep old wood. None are identical and few are ever 6 ft. One we don't grow is Paniculata and it will grow 15 foot tall, so it would probably pass 6 feet in one year. Another we don't grow is the climbing hydrangea that gets up to 80 feet tall. It probably would surpass 6 feet in one year.

The USNA has a good hydrangea site: