Q.Butterfly Bush Is Growing Out(spreading Out) And NOT Growing Up
My Butterfly Bush is roughly 10 years old. It receives all day sun and plenty of water. I trim it each Fall. The last couple of years it hasn’t done as well as it use too. It hasn’t came back in the spring like it use to either. BTW, I’m zone 6. Last Summer/Fall half of the roots wasn’t producing so I cut off the ‘bad part’. It is coming back but slowly. I can not see any parasites or disease on it. The bush is growing/spreading out but’s not growing taller and the blooms look faded. I have given it fertilizer twice but I can’t tell if it’s helped any. How can I get it to grow taller, trim it? How? Fertilize it more? Any suggestions. thoughts, or ideals would be appreciated. Thank you

Certified GKH Gardening Expert
You can count yourself lucky if it's 10 years old. I have never had one come back that long. :)
When you trim it are you cutting it nearly to the ground? They bloom on new growth, so there is no point in keeping any of the previous year's growth. Then they grow back from the roots.
I suggest replacing it. They grow quickly and it sounds like the other one is worn out. In case it is diseased, try to plant a new one in a different spot. If you want to try to revive it, these articles should help:
https://www.gardeningknowhow.com/ornamental/shrubs/butterfly-bush/how-to-revive-butterfly-bush.htm
https://www.gardeningknowhow.com/ornamental/shrubs/butterfly-bush/butterfly-bush-diseases.htm
https://www.gardeningknowhow.com/ornamental/shrubs/butterfly-bush/fertilizing-a-butterfly-bush.htm
https://www.gardeningknowhow.com/ornamental/shrubs/butterfly-bush/butterfly-bush-care.htm