"Are there any kinds of ornamental grasses that will spread,
that is 6-8" high?"

There are, but a 6-8" high screen won't give you much privacy, unless you are very very tiny. ;>)

Assuming you mean 6-8 feet, take a look at the Grass Comparison Chart at Bluestem.ca. They specialize in ornamental grasses for cold climates.

http://www.bluestem.ca/grass-comparison-chart.htm

Hey There.............I did mean inches..............I just want to fill in the area where I dug up/out all my Holly Hocks. It now is 3-4 feet deep/wide of bare soil meeting the level lawn......Privacy is no longer important; that's why I cleared an "L" shape to allow a clear view thru into the garden proper Donn. That dirt is (now that I think of it) is not level with the grass; so a bit higher then 8" would probably be ok. I'll go measure tomorrow; my guess is that a foot high, would allow for a good view. I could figure out how to upload a pic. or url, or even better, maybe I could send an "e" with an attachment to your donnwest@msn.com Would you accept that premise? Have a Good Evening, Jaemy

I'd suggest Carex glauca, AKA Carex flacca. It's hardy to at least zone 4, and can be forced to spread quickly, to fill in an area. Cut it back by 3/4 of it's height, 3-4 times per growing season, and it will send out lateral shoots. In a couple of years, a single row of this plant, in the middle of your border, will entirely fill it.

Boy do I appreciate your attention...............what do you
think of my idea????? If I keep the grass in their original purchased pots; will they be angry & croak????
Also I could pick them up and overwinter them in the basement. I just put my "Porcupine Strictus" IN their original garden center's pots.
They seemed happy all summer within their big pots.
Now I put them downstairs, do I have to a light on for them?
Perhaps occasional watering??? Hmmmmm, Jaemy

Ok, I'm a bit confused .... why?? are you putting your 'Porcupine Strictus' in your 'downstairs'. Why not just plant them in the garden & be done with it?
You might be interested in a study that they did in Minnesota a number of years ago wrt grass hardiness to USDA zone 3!
And .. I can tell you that here in my 'northish' garden Miscanthus sinensis cultivars survive very well.

Here is a link that might be useful: Ornamental Grasses for Cold Climates

achnatherum, I've been planning forever and my cat'l says
Miscanthus sinensis and all the Miscanthus are Z5-9.
At minus -20 degrees, Zone 5 never make it.
I placed the grass Porcupins Strictus below because:
I wanted them to stay in their original pots when purchased.
so I could just plunk them into my clay pots without adding any soil
Don't care if they grow/multiply/spread.
A pot placed into a decorative pot.
Just want tall straight plants.
So,I guess my idea of the basement is to see if they will not die.

I'll know in spring if they croak or not; staying dormant and not freeze to their demise.
A gamble I'm sure.

Do Appreciate your time....Thanx Very, Jaemy

Jaemy,
Definitely, if you want to keep the plants in pots & out of the ground you will have to protect them by bringing them indoors or ...
On the other hand, if you get any snow cover at all - ignore the catalogues & their zone recommendations. Often the information is old & out of date. In older publications the zones were based on where the grasses were growing at the time - not on any good studies like the one done in Minnesota & also not based on gardeners experiences. When I was gardening in a Zone 5 garden with very poor winter snow cover, I was able to grow over 100 different varieties of grasses. Many of the grasses that I grew had previously been listed as zone 6 or 7 plants!
Now I am gardening in a zone 3 (headging 4) with temps well below -20F (-30C). I have been pleased to discover that many of my grasses do just as well up here, if not better! the only down side is that they do not bloom as early.
So ... if your potted Miscanthus survive the winter 'downstairs' you might consider dividing them & trying a couple of divisions in the ground. You may be pleasantly surprised!

I'll email a few pics to see what I'm talking about.

The original nursery's pots are inside the larger as you saw in my email. I snatched them out and
they are now in the basement.
I want more to appear the same as in the pics.
I've no place to put a hole to drop them in the ground nor a permanent place to plant them.
So grabbed the three out of the pots
in front of the garage to take them downstairs. It'll be
my experiment to see if they will survive down there.
Can't manage carrying a larger pot.
I had a hard time just getting
the nursery's orig. three pots
down the steps.
Thnx bunches, Jaemy