True pampas grass, Cortaderia selloana, is listed as hardy only to zone 7/8, although there seems to be reports of its ability to overwinter in other areas, perhaps with benefit of specific microclimates. However there are other OG's that are sometimes commonly referred to as "pampas grass" - Ravenna grass, Saccharum ravennae (syn. Erianthus ravennae), is often referred to as "hardy pampas grass" because of both its resemblance to Cortaderia as well as its increased hardiness.

There are at least 3 cultivars of Cortaderia selloana which are reputed to be hardy to zone 6;

'Andes Silver'
'Patagonia'
'Pumila'

If you have any warmer-than-your-zone microclimate areas in your garden, you may be able to make them work. If you have reliable snow cover during the coldest part of winter, you can use it to protect the crown of the plant from cold. Cut the dead foliage back early in winter, and cover it with a layer of pine boughs. These will catch and hold snow, and create an insulating effect.

Excessively wet soil in winter will kill many ornamental grasses. Most require very sharp drainage, especially in winter.

Apart from that, as GG48 points out, there are other, more hardy OG's which are hardy in your zone. Use the comparison chart linked below, from Bluestem.ca, which specializes in ornamental grasses for cold climates.

Here is a link that might be useful: Bluestem Ornamental Grass Chart

thanks for the link. i saw three in there I really liked, by the way I like ornamental grasses that get taller than me, and the reed, hardy pampas and the korean one, forgot the name. I will look into these.

RR

Find out what you had, it was probably Ravennae but maybe you bought from someplace that unwisely carries non-hardy grass like Lowe's.

Not sure if the wet area is a problem... cold and wet might be bad if the plant is not established yet.

It doesn't do good being wet.. I was reading about it earlier today and the article said," it doesn't like it's feet wet.. Keep away from the water."

I would stay away from pampas grass if I was you.I planted 2 plants 3 yrs ago and TO me they are kinda ugly looking.Not to mention when you cut them back the grass is VERY sharp.Winter always causes some of the clump to die out too.They never look healthy looking. So I tossed mine.

Go with Zebra grass.You wont regret it ,trust me.Ive got about 15 of these and they are spectacular!They get tall just like pampas grass