Interesting observation. I've always noticed that purple Hosta flowers have no scent but the white ones smell SO GOOD!

I have noticed that too. My husband never liked white flowers, but I always thought they were more fragrant. White Petunia, white lilies white star magnolia etc. other colors are fragrant, but I think the whites are most fragrant. but like you say not all white flowers have a fragrance. This year, I am planting all white fragrant flowers on my patio with a few spashes of color. But I must have my white moonflower.

Yes, you are right.
And this is why they make beautiful moon garden subjects too! The reason so many fragrant flowers are white seems to be that they do not need color to attract their pollinators, who are drawn by the beacon of scent, again often at night. The plants you mention are so fragrant, that I think they can hardly need color to attract human acolytes as well.

Best wishes,
Sincerely,
Matt Di Clemente

Interesting. I just read a book talking about that. It is said that if the plant has red, blue , yellow, pink, white , etc, varieties. Most often, white color floer variety one is the fragrant one or the stronger fragrant one. I don't know the science behind it. But that is what the book claims.

I think it must be an evolution thing, if the strong colors attract insects anyway they don't have to produce a lot of scent; so the white ones maybe have to attract them in a different (=fragrant!) way to survive.. I'm not sure if it's true it just came to me reading your post..

Dear Olympia Gardener,

I would love to check out the book you mention, if you would be so kind as to share the title with us.

Dear Fenius,

It may well be. Although Luther Burbank found that all plants had the genetic components necesary for fragrance. He even bred a race of fragrand Dahlias believe it or not. I wish some of these were available today. His intuitive abilities with plants were magical.

http://www.semds.org/index.php?option=com_content&view=article&id=49:experimenting-with-the-responsive-dahlia&catid=35:ancient-history

Best wishes,
Sincerely,
Matt

Matt ALMOST hit the nail on the head...it's not that night blooming flowers don't NEED colors to attract pollinators, but that white IS the right color! White reflects the light of the moon! White flowers also bounce artificial lighting back better than brightly colored blooms.

Many plants are genetically programed to attract the pollinators that are active at night; their nectar becomes sweeter, fragrances stronger, and by their light colors. Moths, of course, are the most typical of the night-time pollinators. Hummingbirds are active in the wee early hours of the morning, too. In some parts of the world, bats are important pollinators; bat pollinated flowers are typically very light colored.

Cool, huh? With plants, as with most natural living organisms, form follows function.

Matt, I was browsing few container gardening books in local library just few days before I saw this forum. It was something new and interesting so I can remember what the book said . I will try to look for the book again next time I am in the library and give you the tile and author.