This time of year, I notice that my bee hives all smell of ivy flowers which the bees are visiting for their last big nectar flow of the year.
It has never to my knowledge been used as an essential oil but it does produce lots of nectar at relatively low temperatures. It will go on flowering until the first frost at which point the bees stop working for the winter.
On the other hand, I will still be working, even getting busier after the summer lull. Summer always seems to be a time when I have relatively little work though with one day a week at a social services project that may well be changing.
Do tell me what other flowers you notice the aroma of that might not be in the traditional aromatherapy toolkit. I can say that everyone has different favourites and I look forward to hearing about them and will look at my suppliers to find out if the essential oils are available.