I agree, the ornamental sweet potato vines are usually grown for foliage ... anyone lucky enough to get flowers is double lucky and I'd say if they get dark purple flowers they are triple lucky! Most of the ornamental sweet potato vines have pale blooms. When viewing photos on the internet one must realize that sometimes pictures are photoshopped and the color is sometimes made to be more vibrant than it actually is. I learned that years ago when I purchased a couple of plants because of photos I viewed on-line and the blooms didn't end up being anywhere near as pretty as the photos depicted!
Check out photos of some of the blooms of these ornamental sweet potato vines (Ipomoea batatas) grown by our members:
'Blackie' has pretty flowers:
Ornamental Sweet Potato (Ipomoea batatas 'Blackie')
'Ace of Spades' are pretty but not very vibrant in color:
Ornamental Sweet Potato (Ipomoea batatas 'Ace of Spades')
'Tricolor' which I have growing in my yard has never flowered but I see one photo in the database showing blooms and they are quite pretty:
Ornamental Sweet Potato (Ipomoea batatas 'Tricolor')
'Sweet Caroline Sweetheart Purple':
Sweet Potato Vine (Ipomoea batatas 'Sweet Caroline Sweetheart Purple')
AND, if you really want a dark purple bloom you might want to try Morning Glories (Ipomoea purpurea), which are quite easy to grow from seeds; the seeds germinate quickly and the blooms are gorgeous all summer long!
http://garden.org/plants/searc...
A very popular variety is
Tall Morning Glory (Ipomoea purpurea 'Grandpa Ott')
If you are looking for something really fast growing, you can't go wrong with Morning Glories! I usually buy a couple of packets of seeds at Walmart or Home Depot every spring and sprinkle them around under one of the palm trees in my yard ... they sprout quickly and twin up the palm trees and are very pretty when in bloom.
