I don't know, but i would buy the plants this year and save the seeds. Then plant, harvest, and repeat. This should work. Good luck:)

Ponyexpress

I grew them last year but they werent a hit with hummers so I wont be growing "petunia exserta" this year but I have tons of seed I would like to get rid of.

Steve would you be interested in doing a trade for some of the seed? If so message me through my members page. I have as I have many different types of seed I could offer.

Mike

It sounds like you already found seed. I also have a ton, and have sent them out for postage. Since the seeds are so tiny, they won't get destroyed by the USPS rollers. So no padding is necessary and postage is 46 cents in a regular envelope.

In my area this is a great plant that is a nonstop bloomer--all through the winter. I hadn't seen much in the way of hummingbird interest either, until a few days ago, when one came to my tiny yard specifically to visit two flowers (I have no feeder). Now the Cupheas are starting to bloom, and I expect those will be the main attraction.

I have some plants that are about to bloom in an area inside with a single compact fluorescent--no natural lights. So this is a candidate for easy blooming under lights. Maybe an ordinary houseplant? I'll try to post when they open in a couple days or so.

This is Petunia exserta that was grown from seed under artificial light. It's sole source of light has been a single 23 W compact fluorescent bulb.