Carol, it's pretty futile to try to propagate most orchids from seed. They take years, and very few seedlings survive (this is the reason why orchid plants are so darned expensive).
That leaves propagating by keikis which is pretty easy with Dendrobiums. There's a hormone paste available called Keiki Grow Plus that you could try, and I have some. Used it on my Phals and Phaius both of which produced keikis very nicely.
Here's what I used:
https://www.repotme.com/orchid...
There's a much cheaper Keiki paste available on Amazon but I've heard from two people who tried it with little success.
Please come over to the Orchids forum and show us some pictures of your Den, and of course if you have any other orchids?
http://garden.org/forums/view/...
