Judemi,
My first thought is that it is way too late in the year for you to grow your own plants but I would think that you may want to consider using dried flowers instead. And you can grow many flowers that dry quite easy using dessicants.
However your post reminded me of Arthur Ames Allgrove who years ago sold Partridge Berry Bowls way before there was any real interest in terrariums. And here is a link to info on such.
Partridge Berry Bowls
Suggest you print it out just in case.
And if you have the money to spare here is a cool site that is selling kits
Berry Bowl kits
And if you want to try to grow Mitchella repens, the Partridge Berry here is one of the few sites that I have been able to find that sells it over the net.
Sun Farm
There are probably over native plant nurseries that sell it.

Thank you so much for the information....I enjoyed looking at those sights and that is exactly what I was looking for.

I noticed last week while at Target they had various sized glass jars with various types of lids at reasonable prices. I have to go get a few this weekend now!