Bill Oliver wrote:

Do I really need to dig up a patch of tulips that has been going
great guns for 15 years and replant them in the same place?

Somehow that just doesn't seem right.

billo

Leave them be IMO. My grandfather had a tulip bed 50 feet wide
by 20 feet long, absolutely filled with every color tulip you'd
ever see. He never dug any if them up, just fertilized.
They bloomed their hearts out for many years, 30 that I can remember.
One of my best memories is him with the tulips.

Minteeleaf