One thing about ornamental grasses is their size - so many would take up a great deal of room in a 5'x4' area, and the smaller grasses often don't have the height.

I'm growing Koeleria glauca in my rock garden - lean soil and no supplemental watering. So far I'm really impressed with this grass - with blooms it's between 2.5' to 3' tall (granted, we've had a lot of rain in May & June this year which could have caused it to be slightly taller than the normally stated 2'). It's blooming now and isn't taking up a great deal of width (maybe 8") - looks great with the dianthus, sedums, gypsophila's, etc. I started them last year from seed.

I grow Overdam in the grass bed - they get the same treatment as everything else in that bed which is well drained soil, full sun and no supplemental watering. It's a nice grass, somewhat smaller in height than Karl Foerster.
The variegation isn't pronounced enough (IMO) to make it special.

Hope this helps.

BTW, I forgot to mention that if your perennials (dianthus, in particular) are blooming well in that bed, chances are it's sunny enough to grow grasses that require full sun.

Pudge,

Thanks for your comments. Is your rock garden full sun? I'll take a look at the Koeleria glauca.

Yes, the dianthus blooms well there. It gets some sun, just not all day.

Try Northern Sea Oats, Chasmanthium latifolium

Northern Sea Oats looks attractive but I've read that it's very invasive. This garden is small and is also right next to lawn. I've read opinions all over the spectrum, wtih some saying NSE is easy to control, and others that it is almost impossible to control.

Does zone have anything to do with this, or only whether you keep it from going to seed? It looks like an attractive plant that it the right size for this garden.

Thanks!

The seeds of Northern Sea Oats are what are invasive, they sprout easily the next year in good conditions. The plants themselves do not spread invasively. The seedlings are not hard to kill or pull up, thou I suppose they could be a nuisance in certain conditions but not as much as your average weed.

I agree with noki. Chasmanthium is a beautiful grass. It's very upright growing, tolerates a variety of soil, sun and moisture conditions, and is reliably hardy. Control of seeding is a snap, because the seedheads are extremely obvious. Let the plant bloom, and as the seedheads start to brown, cut them out individually, with their long stems, and take them inside for the vase. They last forever in arrangements, and if they self-sow on carpet or tile, they're easy to control. ;>)

I collect half my seedheads when the seeds are ripe, and sown them the following year, so I can grow them where I want them.

Well thanks, Noki and Donn, I think I'll give Northern Sea Oats a try. It is just the right size for that little spot.