According to the Brand and Ellis enlarged 3-volume 1870’s edition of Observations on the popular antiquities of Great Britain, it was an old English custom to strew rose petals around the bedchamber and the whole house (or set of rooms) occupied by a couple just married, or just the area at the wedding reception (“bride-ale”) if being held outside the house or at a parish hall for the purpose (sometimes done for poor couples).
But why? Romance? Sex? No….
Thomas Newton, An Herbal for the Bible (1587), p. 225 (English translation of Levinus Lemnius, Herbarum atque arborum quae in Bibliis passim obviae sunt et ex quibus sacri vates similitudines desumunt):
“…to signifie that in wedlocke all pensive sullenes and lowring cheer, all wrangling strife, jarring, variance, and discorde ought to be utterly excluded and abandoned; and that in place thereof, al mirth, pleasantnes, cheerfulnes, mildnes, quietnes, and love should be maintained, and that in matters passing betweene the husband and the wife all secresie should be used.”
So the two rose meanings here are mutual sweetness of temper, and mutual discreet privacy (keeping one’s talks “under the rose”).
A far cry from our interpretation of wedding roses!
This enlarged edition of the book has a lot about English wedding customs in Volume 2, including a very interesting section on giving brides a pair of “wedding knives” to be their daily work knives, constantly hung on the belt.