Q.Late Winter/early Spring Prep For Rudbeckia Mass Planting?
I have a 24 ft X 3 ft bed which is a “mass planting” of Black Eyed Susans (Rudbeckia). There is a LOT of “old growth” left from the previous season – mostly dry, dead, standing stems. I’m thinking about a six inch high “hair cut” with a hedge trimmer to prepare for spring. Is this a passably workable idea?

Certified GKH Gardening Expert
Absolutely! Trimming death material is a good idea. By this time, they may have already re-seeded. It'll be a nice full area when it comes back.
Here is an article for more information on the flower:
https://www.gardeningknowhow.com/ornamental/flowers/black-eyed-susan/black-eyed-susan-flower.htm