Nick -- generally any plant with a name like this -- Miscanthus sinensis 'Little Fountain' -- is a cultivar that is different from the main species in some way: different color, different form, etc. They make new 'Little Fountain's by cloning existing 'Little Fountain's. If you tried to collect seed from them the new plants wouldn't necessarily come out the same as the parent plant -- there's a good chance they would just look like regular M. sinensis instead of 'Little Fountain'. Cultivars are often patented so that you're not allowed to grow them from seed anyway.

You can buy seeds for non-cultivar M. sinensis, but have you thought about using a native grass instead? You can buy seeds for those much more cheaply than you can buy cultivar plants, and the value to wildlife is higher.

I'm sure members of this forum could give you some suggestions if you could tell us a little more about your site: what zone, how much sun, type of soil.

Thank you! I am right on the line between zone 3-4 and the spot I'd like to put the grass probably receives around 5 hours of direct sunlight per day. I am not quite sure what type of soil I have there. All I can say is that it is not sandy, I've never had it tested before either.

Do you care how tall the grass is? One (shorter) alternative that you could plant from seed would be Deschampsia cespitosa. It would do better in part shade than Miscanthus, but once it really gets going it would compete well with weeds.

My sense is that the effort level for seeding many ornamental grasses is fairly high compared to using nursery seedlings, especially if you're trying to get a nice pure stand of something. There will be a lot of weeding the first few years. You are probably best to seed them into plug flats (get the deeper ones) and then transplant them into place. This will make it easier to identify exactly where they are and weed around them, plus it's easier to keep an eye on them (and keep the soil moist) in flats.

Personally, for only 15 feet of grass, I'd use nursery-grown seedlings.

Thank you for the advice! Basically I'm just trying to make a screen between the woods and my lawn without building a wall, which wouldn't look very nice. If you have a better idea of what would be able to separate the two I'm all ears!! Thanks

I would rethink using Miscanthus. I doubt it would be adequately hardy for you. Most cultivars are only rated to zone 5, some only to zone 6 or 7. It is also a sun loving grass, so does best out in the open and unlikely to thrive where it might receive much shade, like on the edge of a wood. And many cultivars do not set viable seed and those that do would not necessarily come true to form from seed.

Ornamental grasses are not very likely to be very efficient at deflecting any weeds creeping in, either. You would be better served by clearing out the weeds manually from an appropriate depth of planting area, leaving just what native species might be present and then plant the border between the lawn and the woods with woodland plants of your choice. I generally recommend keeping a "no-man's land" of a couple of feet or so clear before the added plants are located as weeds will always return and that empty space will allow you to get back there more easily and keep things cut back. Once or twice a season should be sufficient.