Plant them in a large pot, but bring them indoors for the winter. Acclimatize them in the spring. A vicious circle, but it pays off. They will do well in the garden in the summer, but will not survive the frost, so you must bring them indoors.

I do the same thing with my brugmansia bushes / trees. Extremely fragrant, but very fussy plants. Nevertheless, I have quite a few different varieties.

If we want the luxury of these magnificent plants, then we have to put a lot more effort into their maintenance than most plants would require. ... a price we have to pay.

No, neither gardenias nor jasmine would likely survive in Mass, although possibly some of the most hardy kinds might make it in sheltered microclimates on Cape Cod, or on the islands, where the Atlantic moderates the cold in winter.

I do have a suggestion for you, though, for an unusual blooming shrub with wonderful foliage and fragrance, and that is a buttonbush. It's actually a native plant, likes wetlands and does ok in semi-shade, and the flowers are round balls that smell heavenly, spicy and similar to cloves. Try a google search for it, and you should be able to find information and sources. Mine is about to bloom, and I always look forward to it. Bloom time is for about 2 to 4 weeks in mid-summer.

Actually, I just bought a Jasmine plant yesterday. I was told to do exactly as I had suggested above.

Now I have to check out this buttonbush plant. Thanks for the tip, denninmi.