According to Darke, it probably won't set viable seed in your zone, but he also says that it's "strongly rhizomatous." That means it could very well spread by rhizome, like some Bamboo does, although Darke says "invasive potential unknown." You could probably keep it in place by regular root pruning.

interesting, Thanks for the reply. That information has me worried, if it spreads by rhizomes, does that mean it will send up plants 10 feet away from the original? or that the clump will get bigger and bigger? thanks for your help I'm new to this stuff.

How tall has it grown for you. I've read that it may be cold hardier than donax, so I may give it a try.

it has only grown 3 ft high I planted it in august though. We'll see what it does next year.
I've also got a sunny spot where i'd like to try some donax to block a view of the neighbors van. not sure where to get donax. I guess I could just find someone who has some and sneak in at night and steal a rhyzome. :) just kidding, I don't think anyone I know even has this kind of plant.

I have planted Arundo donax for at least 2 years which from 1 to 5 plants,to my surprise,recently these plants grow very fast,without my notice there comes out 3 new more shoots suddenly only after 3days within my only 1m*m area.I'm afraid that after some days they will be invasive to the neighbour og grasses.:).welcome u come here to steal some.:)

Hey Mang, I don't know where you are, but there is a guy in North Ogden/Harrisville area that sells donax. Also, Valley Nursery in Uintah sells it.

I'm in draper, I'll check out valley nursey, I got my arundo formosana at Glover nursery, they have a lot. There is vurtually no information on the formosana anywhere, I'll post a pice of mine as soon as I can get pictures transfered from my camera to my computer.

There is a big lack of information of the arundo genus in general. Most things on the internet are about it being a invasive pest. Also, information on how it grows in the north is even more lacking.

Mang, if you want donax, maybe post it on the ornamental grass exchange.. Maybe you could find somebody who would send some for shipping cost.

If your arundo Formosana gets out of hand, I would be willing to take some off your hands in the future for shipping cost.

I'm sure I'll be able to share some regardless once its established, seems like a rare plant. (arundo formosona) It will be fun to see what it does next year.

I bought some donax on ebay, I'll probably keep in in doors in a pot until spring then plant it if my wife will let me. she things it's going to take over the neibhborhood

To spread fast, arundo donax probably would need high moisture such as by a body of water. If your planting it in a yard and don't irrigate it you shouldn't have any problems. I will keep posted on what its doing here since mine is planted near a stream that runs 6 months of the year. The donax was under a couple inches of water during big spring rains.

I do irrigate though, everywhere. So maybe this one is not such a a good idea in the garden landscape.