As a florist, i've made A LOT of Bridal bouquets. We all know that wedding flowers enhance the bride’s beauty and the bouquet gives her something pretty to hold while walking down the aisle, but the true origin is not completely clear. I've summarised the most common reasons that explain the tradition of the wedding bouquet:
To mask any unpleasant scents
This first reason is far from romantic. This story goes back to the 15th-century when people didn’t bathe that much. Back then it was most common to get married in June because everyone took their yearly (!) baths in May. With their baths already a month ago the brides didn’t smell too good. So that’s reason numero uno why they (used to) carry wedding bouquets: to hide their body odour and prevent their future husband from running away.
To get the happy couple in the mood
This reason dates back to the Roman era. The Romans did not have bridal bouquets, but garlands that symbolised a new life and fertility. Later on, this tradition evolved and aphrodisiacs such as Dill were added to get the newlyweds in the right mood.
Ban evil spirits from the wedding
Reason number 3 is a smelly one. During the Middle Ages, people were a bit more superstitious than we are now. In order to banish evil spirits from visiting their wedding, the brides added some strong smelling herbs to their bouquet. In fact, if you look through photographs of vintage weddings, you'll often see the Bridesmaids carrying a bouquet that's just as big as the Bride's! This was thought to confuse the spirits as to which one was the Bride.

The language of love
This reason is more in line with our modern uptake on wedding bouquets. In Victorian times it was custom to send your lover messages through flowers. As you probably know, each flower has a different meaning, according to the language of flowers: floriography. Due to this romantic association flowers became a new wedding tradition which we gladly embrace.
To protect the bride
This reason mostly explains where the bridal bouquet toss tradition comes from. Several centuries ago a bride was considered very lucky. People thought that some of this luck would transfer to them if they were able to rip off pieces of her dress (seriously!). To distract the wedding-goers the bride began tossing her bouquet in the eager crowd. When everyone attempted to catch the bouquet the bride and her husband would quickly run to their bridal chambers! Due to this new tradition, wedding attendees stopped tearing off the bride’s dress (thank goodness!).