Alina is right but sometimes needs must. Unfortunately I'm having to clear out a whole flower bed because this horrible weed took over early in the year while I was poorly and unable to get into the garden. I don't know what it is called - well I call it something unprintable..
So I am digging up every shrub and perrenial and getting them back to bare roots to eliminate every bit of this monster and then replanting elsewhere. So far I have moved, amongst many others, a mini Lilac tree, Solomon's Seal in flower, Peony in flower (that drooped a lot but I cut off the flowers), Lavatera shrub (which drooped the minute it came out of the ground but is fine now), Irises just about to flower, Lupins in bud, Cotoneaster in flower, Red Hot Pokers in bud, Asters, Echinacea, Erginum (which I divided into 5 and it is two weeks in the new place and doing better than ever) - I won't bore you with the rest. I've lost just one so far but I was losing everything under the weed.
I'm still digging up and moving but as Hubs says, they have two chances. I water every day and they all got some new compost and a bit of fertilizer into the hole before planting.
Good luck. <h1 id="title_div" class="photo-title"> </h1>