Checked out the two redwoods I planted in Harvard Hill park a few years ago, when they were below waist high. This little park sits below the A4, just east of the Chiswick roundabout. I chose redwoods so they would (eventually) be visible from the elevated dual carriageway. Ron grows them on his garden and we travelled up to collect them as excited as though we were picking up a new puppy.
Now they already tower well above my head.