One of the things that plant breeders have been focusing on is the longevity of flower blooms, whether they are grown for cut flowers or for how long they bloom on the plant itself. So why would this affect the fragrance of our beloved flowers? For most flowers, aroma production and length of life are linked by a plant hormone called ethylene. More ethylene makes the flower fade sooner, but it also creates more scent. So while plant breeders have been prolonging the life of blooms by tinkering with this hormone, they have also weakened and in some cases removed the scent altogether.
My grandmother was an avid gardener and every year she grew Sweet Williams (dianthus barbatus)
in her yard. I always liked them, even when I was a child, and l loved their scent. For the last two years I've had them in my own yard, but they don't have nearly as much fragrance. In my opinion it's not worth the trade off, so if you are like me, find yourself some old-fashioned varieties and enjoy their scent once more.