You can purchase wave petunia seeds from many online and paper catalogs. I've not seen the sweet potato vines from seeds, don't think you can get it "that way" as they are tubers. I love them too and here is my stategy:

Early in the Spring I buy one of each color I want at the garden center. I try to find really robust, full ones, but still in small pots so they are cheaper (even these go for $4 a pot here). Then I take them home and make cuttings, dipping the cut ends in rooting hormone. These cuttings are placed in a homemade propagation box. Just a clear sweater box, filled with damp promix with a porous clay pot full of water in the middle. This pot then keeps the soil moist. I bury the cut, hormone dipped end in the soil and a leaf or two sticks out above. I place the box in an indirect light (sunny but not hot)on a table near a window in my den. In a week or so roots start to form, in 2 weeks they are ready to pot up as small plants and grow on (inside, till its warm enough to go out). I can't remember exactly WHEN I do this, but it's not till at least Mothers day I don't think!

Our local Lowe's has wave petunia seeds. They are limited in color and higher than the other seeds but they do have them.

Jackie

I agree with Nan - I've found that to be a much more economical way to grow waves. You can usually get 4-8 plants out of a $4 nursery plant, and the seeds for waves are pretty much that price for 8-10 seeds. The cuttings reach blooming size much faster, adn they grow to be much larger plants in my garden at least. I've tried waves from seeds by wsing a few years now, and although they work, the cutting route has been much more successful for me.

Sweet potato vines are not something I've seen from seed etiher, but you can save the tuber from this year's plant and overwinter it to start it again next year. I believe that those work from cuttings also.

I haven't tried to wintersow geraniums, although you can buy those seeds from catalogs. I think that those like to be started indoors under lights in order to get plants to blooming size. Again, I do geraniums by cuttings - they're easy to propagate that way, and you can keep them as houseplants over the winter. THey typically need a trim in the winter anyway, and you can use those cuttings for more palnts.

Spartangardener... I've was just talking about doing cuttings with the sweet potato vines, I've not tried it with wave petunias but now I think I will! Thanks!

Actually, I HAVE tried it with geraniums and it works the same (buy one plant, cut it up) but I did lose a lot of the geranium cuttings in the prop. box last year. I think the environment (that the sweet potato vines seem to love) is just too damp for the geraniums. Only about half the cuttings lived.

You're so right, I did forget that sweet potato vine was a tuber! thanks so much for the help on how to do cuttings. I will try Lowe's for the seeds too and try a few that way.

I have grown geraniums from seed quite a few times now. Stokes seeds has a nice selection of them, more varieties than I can get at the nursery. For my zone I need to start them quite early (January) so they bloom for much of the summer. I have had GREAT success with starting them from seed. A little bottom heat and they have always sprouted for me in less than a week. This year I am going to try to take some cuttings from them later in the season and winter them over in the house.
I'm not sure about ws'ing them, as I would have to start them to late in the season for my climate that they wouldn't likely bloom until late Aug or Sept for me then.

Oh, Stokes also has wave petunia seeds. They are quite spendy so I just do like the others and buy one of a couple different varieties and take cuttings. They root so easy. I will actually go "halvsies" with a friend and we swap cuttings.