I would like to know what grass this is? They're so beautiful! Or do you know a grass that looks like this that I can grow in my area, zone 5 and that it's perennial?

Thanks!

In zone 5, you could try several Miscanthus sinensis varieties. Zone 5 cold hardy include:

Purpurascens (quite cold hardy and a softer, wider blade than the species, as this is not thought to be a sinensis)
Autumn Light
Cabaret
Cosmopolitan
Graziella (blooms a bit earlier than Gracillimus, which some winters doesn't even bloom in zone 5)
Malepartus
Morning Light
Nippon
Sarabande
Silberfeder
Strictus

http://www.bluestem.ca/miscanthus-graziella.htm

Thank you so much! :)

Graziella foliage is a bit finer and narrower than the miscanthus in the photo, but the plumes will be similar.

You have a Miscanthus--no doubt.

Miscanthus seed heads are very distinguishable from others.

Good thing is that the nursery carry both the Erianthus and Graziella. :)

About my question earlier, do we cut them during winter as short as 1 foot? It's because, my officemate has an ornamental grass and he told me that he always cuts it around November. He doesn't know though what OM it is. I actually saw it 3 weeks ago. It was dead and 1 ft tall. It was like bamboo sticks that are 4mm-7mm in diameter.

I would not cut back until after winter, in early spring, just as new fresh basal growth becomes visible. You can take the miscanthus down at that time to a few inches if you choose.

I need your help again. I found a new grass but it's more gorgeous. Do you know something that is very similar to the picture below buy hardy in my area, zone 5?