I don't have great luck with fall planted Arundo donax even if they are nursery grown in pots. However, I have never done anything special with my Arundo donax to keep it happy thru a zone 5 winter (London, Ontario area) and I do know people that are growing it in a COLD zone 5 in the Toronto, Ontario area.
Personally, I think it is important to leave the stalks on this grass - cut open stems hold water & freeze. Colder areas would definitely benefit from a winter mulch.
It is definitely worth a try.
This year I moved a small clump north to our property in a zone 4 (bordering on zone 3) - it will be interesting to see if it survives!
The variegated cultivar is not nearly as hardy but, it too has survived more than 10 winters in my zone 5 garden.

a.

That's great thank you!
I will mulch well being that I mulch plants close by to the clump. It was spring planted so hopefully you are right and that will be of benefit.

I have the variegated arundo in my yard. planted it last year,the potted clump doubled in size in zone 5.no mulch but we did have a lot of snowfall.

ooh, this would be sooo cool to not have to try to get mine through the winter indoors. now i'll be heavy mulching around/through it. thank you all for the encouraging info.

randy, what do you mean 'the potted clump'? is it in a pot above/in the ground?
best,
mindy

I was just referring to the pot that came from the nursery,yes it is in the ground,no pot.I am sure the heavy snow cover helped insulate it.this year I will mulch heavy good luck

Hi everyone,
First time posting here. I just love the orn. grasses!!!This is a photo of my arundo grass. I have had it in my holding garden for about 4 years, it gets so tall that I can't decide where to put it. My husband took this photo this past fall!!

Great specimen !!!!!!!!!!!!!

Mulchy - what a lovely chunk of Arundo donax. Why not leave it where it is, it sure looks happy.

Reporting in from my 2008 posting. My A. donax did indeed survive the winter of 2008/2009 in my zone 3/4 garden. It was healed into a berm of soil in 1 gal pot. It didn't put on much growth but it did survive & is now planted in a permenant location in the garden - I sure hope it survived this winter as well.

sure is a beautiful grass .
I've been trying to get this one .I don't understand why it is so hard to obtain no nurseries around here carry it.
I fist saw the varigated one at the zoo. Wow so impressive thanks for sharring.