From time to time, I find couples or families who have grown their own flowers; a bridal bouquet, a table setting, room decoration or for presentation at a funeral.
Gardening is not my forte but Kevin Rodrigues is a gardener in the USA who has some great advice on growing roses. Yes it is an American article and so temps and measures are empirical but still a good read if you want to grow your own:
https://gardeningmentor.com/how-to-grow-roses/