I would sink them pots and all into the ground, and then mulch around them, or put leaves around them, and plant them in spring. Make sure you keep them watered until the ground freezes.

Pampas Grass? Cortaderia? It is unlikely that it will survive a zone 5 winter, no matter what you do with it.

However, if "Hardy Pampas Grass" is a nickname misapplied to a genus other than Cortaderia, it might survive; so just what is the genus of this "Hardy Pampas Grass?"

The fescues ought to survive if you sink their pots. Place sunken pots where they are sure to drain freely.

The Pampas Grass is Saccharum ravennae 'Erianthus' Hardy Pampus. It will do just fine here is zone 5.

I am burying the grasses and hostas in a pile of leaves in a fully protected area by the front door. The leaves should act as a cold bearier and mulch. Hopefully they wil survive this way. My Japanese maple root stock survives doing this so I'll give it a try.

Grancu, I did what I should have done first: googled "Hardy Pampas Grass" and found that, yes, it is Sacch.r. (aka E. ravennae) and hardy to -20°F.

I sometimes sink pots, and usually they do okay. Drainage is keyÂthat and keeping the crowns dry, so mulching around the pots' sides is good; mulching their tops, not so good.

what about not-so-hardy pampass grass?

Cortaderia selloana 'Pumila' is more hardy than 'Rosea' or straight species . Sacchrum ravennae is just about as ubiquitous as Cortaderia around here . The one to look for in zone 6 is Saccharum arundinaceum . This monster gets to 12-14' with inflorescense . It will hide your neighbors collection of rusted out cars . Zone 5 sounds chilly . Sinking pots and raking leaves will work , pine straw emits a lot of heat .

I had purchased two dwarf pampass which grew beautifully in pots (summer 2004). One even plumed. I overwintered them in the pots, one outside, one in the garage. Neither one made it. The pots were too large to bury. I'm now looking for grasses hardy to zone 3 that will survive in the pots.