To reduce the impact you could cut one stem down this year and the other next year. I don't know your climate so I can't advise on the timing.

You have several options :-) You can hard prune if you wish as soon as the bloom cycle is finished but that may eliminate flowers next year (it WILL produce new growth but perhaps not enough to mature through this season to produce a good flowering next). Alternatively, you can cut it back intermediately (by 1/2 or more or less) or remove one major stem completely back to the base and follow a similar plan next season.

see link ... a 3 year process ...

i would speed it up a bit.. take one of them off now .. off the branch with two ...

i would take the second in fall ...

we are wanting it to sprout way down low ... so you will get fresh... new.. vigorous growth ... because there will be no insult to the roots.. plus all that new sun ..

the following spring.. after it flowers.. i would take the last old one down ...

ken

https://www.google.com/search?q=rejuvenation+pruning+of+flowering+shrubs&ie=utf-8&oe=utf-8

actually.. if you have the power .. like a teenager .. lol .. i might move it another 5 feet from the house ... if you have room ...in early fall ...

its could be a brilliant specimen if better sited .. ken

Thanks all for your helpful comments. I do have better locations in the yard where it would look great so perhaps I'll take one stem now, move it to a better location in the fall and take another stem next spring. I really appreciate the advice :)

It grows very easily from cuttings so you could make some more and put them elsewhere on your property.

You can mow this thing down and it will come back. I had to move about six of them last year and to make it easier we cut them down as low as we possibly could. That means we forgo blooms for a year, but they come raring back. It is more elegant to do the classic rejuvenation pruning, but I seldom have the patience.

Haha ... I often share your lack of patience! This spring was the season to rejuvenate my entire rear yard. With so much going on I may just take my chances and "mow this thing down" and move it. Appreciate your feedback :)