Being oils and alcohols, fragrance can often be undetectable, not only due to the individual nose's ability to perceive them, but also due to climatic conditions. Too hot, too dry, too windy, too cold or too wet and they may evaporate and blow away quickly, or not even evaporate at all. Like when you apply your cologne. Sometimes, you can smell it for hours. Others, it dissipates nearly immediately after you put it on. You might try cutting opening buds to bring indoors to fully open. In the house, the air is much more still than outdoors. Often, the humidity is higher unless you dehumdify it and it can be warmer than outdoors. This has often permitted "unscented" blooms to be appreciated for their scent. Gene Boerner, the famed breeder for J&P, often tested for fragrance in his seedlings by putting blooms under his hat on his head where they would be warm and humid. I grew Brown Velvet for years, never appreciating its scent, until a friend wrote to be brag on what a wonderful scent it had. I opened some indoors and found they did smell quite good. If you still can't smell them opened indoors and in other seasons, perhaps it is your sniffer, allergies or perhaps the effects of some medication you might be taking? Anti histamines knock out my sense of smell and much of my sense of taste. Then, there are some scents and tastes I am simply immune to. Tropicana has been touted for decades as having a rich scent of ripe raspberries, though it is "green and wet" to me. The scent of Tea in roses smells like clean Tupperware with Orthene, definitely not a desirable scent to my nose!