The stink on roses

    Philly’s big horticultural event is almost over, and although you can still catch the Flower Show this weekend, starting Monday it all comes down.

    That’s when we can turn our attention back to our own more modest home-scale garden projects.

    As they consider what to tackle in their gardens this year, a number of people have been asking questions about roses, so I thought I’d take a stab at some explanations in my next few posts. Let’s start with fragrance. We all know the way a rose is supposed to smell, but why do some roses lack any scent whatsoever?

    In general, the fantastic, super stinky roses that can fill a room or a whole garden with fragrance are almost all varieties that were introduced before around 1850. This date roughly coincides with the transition from the Miasmatic theory of disease to the Germ Theory of Disease. The Miasmatic theory held that illness was caused by bad humors and foul air, and that people could protect themselves from becoming sick by overlaying the bad smells in the environment with good smells—usually in the form of flowers.

    The tradition of corsages and boutonnieres originates during this era, as well as the word “nosegay”. When passing through a noxious miasma, the wearer could turn his nose to his lapel, inhale the fragrance of flowers and, protect himself, it was thought, from airborne disease transmission.

    Of all flowers, it was the rose that was most supremely useful in this application. Roses are among the plants with the most volatile essential oils. When captured, the oil in roses remains stable for long periods. Roses were bred for strong scent as far back as the Crusades. By harvesting the petals to dry or distill, it was possible to store up a year’s worth of necessary good smells.

    Once Germ Theory was discovered, fragrance in roses was considered less important, and breeders started selecting for qualities like variety of color and longer blooming periods. Scent fell by the wayside, and today very few new roses (or any other newer plant) have much in the way of the scent of their ancestors. When it comes to a good fragrant rose, older is better when choosing cultivars.

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