Very few ornamental grasses would be invasive in your climate, because most of them won't have a long enough growing season to set and ripen viable seed.

For lots of good ideas, check out Bluestem's website linked below. They specialize in ornamental grasses for cold climates, and have a very informative website.

Here is a link that might be useful: Bluestem

Thank you. That website is awesome!

I shied away from ornamental grasses for years because I thought they were all invasive. Not. Many OGs are clumping forms that are very well mannered. I've had no problems with various Miscanthus varieties (Adagio, Morning Light, Little Kitten), Blue fescue, Blue oat grass, Carex elata (Bowle's golden sedge), Muhly (Muhlenbergia capillaris), Hakone grass.

I am growing Prairie dropseed, which should grow well in your area, for the first time this summer. It is also a clumping grass, so shouldn't be invasive.

I've had moderate problems with River Oats (Chasmantium latifolium), which reseeds heavily. Moudry Fountain Grass is also known reseeding, but I cut off the seed heads to prevent that. Tried that with my river oats, as well, but apparently didn't do it soon enough because I've had tons of little seedlings popping up this year.

I would have to disagree with Donn somewhat :) about a long enough growing season to set viable seed. Certainly this is true of any warm season grass, however the cool season grasses do have plenty of opportunity to reseed. I rid my yard of Blue Fescue (Festuca glauca) for that very reason.

I still say (and I'm repeating myself once again) that a short season grower just can't go wrong with any of the Calamagrostis x acutiflora such as Karl Foerster, Overdam, Avalanche or Eldorado. Aside from Avalanche which I've yet to find, all are hardy in my zone 2B garden, not the least bit invasive and provide interest throughout the whole year with zero for maintenance except the spring cut.

There are many grasses that are always listed as zone 5 and above that are much hardier (I've got some in my yard). If I can fill my yard with ornamental grasses then your zone 4 garden should be no problem.

Hi Mikaela,

I live in SD and grow the following grasses:

prairie dropseed
Karl Foerster
blue fescue 'Elijah blue'
northern lights
panicum virgatum 'shenendoah'
panicum virgatum 'northwind'
little bluestem 'blaze'
variegated purple moor grass
northern sea oats
miscanthus sinensis 'sarabande' (new)
ribbon grass

Northern sea oats seems to do better with mid-day shade. Plus, it will easily reseed.
Ribbon grass is, well, ok. Variegated purple moor grass does best in mid-day shade---but, one of my favorites---a small grass that sits at the front border.

Otherwise, I have no problems with any of these being "invasive".

Thanks everybody. So far I have a miscanthus and Karl Forester. Ace had everything marked down 75 percent and those were there. I will continue to look and see what else I can find. It is funny because I wasn't going to get the miscanthus that I did until I saw it at Menards. The dried grass was all twisted like cork screws. It looks cool.