I've seen them reach 6 feet, but that is quite tall - usually happens in cool, wet weather, especially if the plant's in shade. Usually they've finished flowering, or coming to the end of flowering by now, certainly in the south, but this year, with the weather, all bets are off....

I saw a scene in Midsomer Murders where they were standing in an area of foxgloves that were taller than the actors. Quite impressive.

Thought mine was tall but it's puny compared to yours.

We've had a few a lot taller than us but most aren't.