Why not take them from the pots, trim the roots and place
them back with new soil. Just a little bit of work but the
plants will love it. I have two among my many that are 8-9'
tall that needs more watering because they're potbound. I'll
trim the roots and add more soil in the spring. I prefer to
keep them as trees. Good luck!

Margaret

That's a lot of years in pots! The experts will give you better advice, but you might want to start cuttings, and also trim the roots on your original brugs and re-pot.

Ha, ha Margaret, we were posting at the same time, but your response is more thorough!

I was talking to someone at the local botanical garden about their brugs. Theirs are also quite old and tree size. They said that by the time they reach that age and size the blooms decrease so they take cuttings and start all over. This might only pertain to container brugs, which theirs are, because I've seen huge specimens in frost free areas that are just covered in flowers.

Karyn...it probably is true for those in container. I have
a pink one in ground and that baby is huge...especially in
width and has tons on blooms. I've propped it up this year
because it has approx. 4-5 Y's that are actually the size
of a mature plant. When I strip her down, I'll tie the canes
up for storage and prune back a bit. Last fall I had way
too many very large cuttings in too many large containers.
Gotta scale my cuttings down somehow.

My mature ones are 8-12 years old. This year I am closing down my little GH, reducing my collection to 7 Brugs and storing them in the basement. ( I plant mine in the ground every year though, then dig them up, pot them and store them semi-dormant over the winter.)
Last year I was anticipating doing this reduction and started cuttings of each plant I am keeping, DH can not lug 5 gallon trees to the basement. My trees however are going to good homes. By planting them in the ground and rejuvenating the flowering branches each year, even my old ones continue to flower well. As was suggested, I would either remove the plant and trim back your root balls and tops severely OR plant those babies in the ground!! You and I are in the same growing zone and I get this result in the 4 short growing months you and I have.....

French Canadian, started from a seed in 2003( taken just last week on the 3rd flush of the season)...
{{gwi:544943}}

Exotica, I think I got as a tip cutting in 2000, taken 3 weeks ago on the third flush of the season....
{{gwi:544945}}

Ruth Ann you really do grow the most amazing brugs, especially considering the zone you are in.

It does take some work, but I would unpot, remove as much or all soil, trim roots WAY BACK, cut off all foliage and trim off all the smaller branches or to secondary branches (hat-rack effect). Repot in small container with fresh soil, store dormant for the winter. Next Spring your plants will be rejuvenated!