I don't and it doesn't seem to make any difference in the amount of blooms I get (lots). I should because the seeds they produce add lots to my weeding. I am from a different region/climate, so maybe someone with a more regional perspective could be of more help.
Well, I guess the key word hewre is, "supposed". I don't thi nk that one is supposed to remove the dead flowers. I do however because I have so many and I like to fill up my compost bin with them. I remove some when they are still greenish and soft and then later on I remove the rest which has turned brown and crispy. Some years I don't do anything with the deas flowers at all and remove them in October and/or March when I am pruning limbs anyway.
pruning butterfly bush Cut back in February to 1/3 and take some cutting from the prunnings, stick them in the ground and they'll root, use thick stems (but this applies in the UK). Doing this keeps the flowers at head high.
I had 2 bushes about 3 feet apart. I cut the pods and dead flowers off of 1 plant and not the other. The one I didn't deadhead got taller and the blooms slowly decreased, but didn't totally stop. The other bush got wider, denser and had lots more blooms until frost. I let the one go to seed just to collect the seeds. Now I trim all of them.
Actually, I had 3 butterfly bushes and tried one cutting away the dead flowers and one keeping the dead flowers. The one that I cut the dead ones away, had way more new blooms then the other one. I cut the dead ones away on the new I just got. And its sprouting off new flowers everyday.
