Contact a Wildlife Officer, A Nursery, Perhaps a old fashioned Feed and Seed dealer.
There is some plant , bush , ...something that offends and keeps the pigeons - so I have heard.
Long time ago I had an elderly couple that were really knowledgeable such matters. Had a Herb garden , regular garden , flowers and whatnot.
Reason we had no mosquitos or snakes around our pond was because back when the platt was new - they brought ducks in - on purpose, and sure enough - we didn't have Mosquitos , snakes around the pond.
They mentioned some plants , and stuff were planted in with the rose bushes and other stuff to keep critters, pesky flying critters like wasp - away.
I forget what they said sometimes worked for Pigeons. They thought a shotgun was the best - in lieu of that, something planted was suggested.
Did not recommend dousing places with Bleach , or Ammonia. Now that kept raccons out of the trash cans...