Cortaderia - pampas grass - is about the most drought tolerant of the larger OG's. Next would be the switch grasses (Panicum) and then followed by miscanthus and calamagrostis.

On the whole, most ornamental grasses tend to be pretty DT but there are variations. Miscanthus would really perform and look best with bimonthly watering during the summer months. Pampas grass can get by with virtually none, once established.

If you are in the local area Cortaderia has become a weed here. Yucca might work for you.

portland, oh and exposure is full sun to part sun.

i could probably live with bimonthly waterings for a couple years.

i would go with yucca, but i do want something faster in this spot.

any thoughts on arundo or panicum?

I do notice around Portland that the yucca flower stalks topple much more often than the pampas grass blooms. Haven't noticed any weedy activity for the pampas.

Infesting ditches, roadsides and streams in the Seattle area - planting should be discontinued. Have seen several individuals bunch up around the entrance to an urban culvert, where the potential for debris to back up around them and clog the opening seemed pretty high. Maintenance people having to get down in there and remove the firmly rooted, razor-leaved grasses probably not a fun prospect; not a good location to be using glyphosate.

Genus is so prevalent in coastal California that many assume it to be native.

Pampas grass is growing all over the coastal cliffs and roadcuts in northern California. Orange Altsroemeria grows in the roadside ditches.
I like Miscanthus over Pampas Grass for several reasons. The blades don't cut and it hasn't self seeded for me. Not as large either. Division is easier than Pampas Grass
I also grow Miscanthus giganteus. I never water my Miscanthus.
Yucca is dangerous. I had a variety called 'Adam's Sword'. While walking by it one day I noticed a weed growing close to the crown. I quickly reached down and in to remove the weed and got poked in the cheek with one of the sharp pointed leaves. It penetrated my cheek and got my tongue too. Needless to say that plant was history within minutes. I have kids.
Mike

The panicums are excellent choices. Lots of color variation, minimal maintenance, decent drought tolerance. Not quite as large as most miscanthus cultivars overall but still pretty substantial grasses.

Arundo gets huge but is a water lover. And it is also quite prone to invasive tendencies. For this area, I would consider giant reed more of a problem plant than the pampas grass. I don't find it wildly attractive either, compared to many other OG's.....kind of coarse and unruly looking. But that's a personal preference :-)

Arundo is a ditch weed in California but is never seen outside of cultivation up here as far as I am aware* - perhaps you are thinking of Phragmites, which forms large patches in some local ponds. Unlike Cortaderia, it is pretty much a wetland obligate outside of cultivation, whereas the Cortaderia is appearing along roads here as well as in streams and ditches.

While getting plants at a local wholesale yard recently I saw another company drive out with a pampas grass propped up in the back of the truck, its mature-looking plumes probably ready to scatter seeds all the way to the job site or other destination.

*I don't think I've ever seen it flower in this area, so presumably local escaping from cultivation would then have to be accomplished via vegetative fragments

This post was edited by bboy on Tue, Oct 22, 13 at 15:06

probably going to be miscanthus. got lost at the joycreek site looking at all the varieties. THANKS EVERYONE!

Very popular item. Note that the spent leaves detach and blow around after the top shuts down each year, making the plant quite the Messcanthus.

As it is evergreen Miscanthus transmorrisonensis doesn't have this drawback - there is no big annual shedding of all the leaves at once. You might like to have an evergreen grass for this planting anyway.

You might want to visit Scott's blog, he is in Portland, and he has lots of excellent grass photos. I think Big Bluestem is one of his favorite larger grasses, it is a native so has advantages and especially probably more drought tolerant, though I never water my Miscanthus sinensis 'Zebra' grass.

Here is a link that might be useful: Scott

Not native out here, of course - the eastern half of the country is more different from here climate wise than some other parts of the world.

There's always Miscanthus 'Giganteus'.
I don't water it at all. If I did , it would get larger.
I cut some floppy stems off just prior to taking the picture.
Mike

how does giganteus hold up in the winter?

i am hoping to do the chop in late winter, let it grow rest of the year routine.

All the non-evergreen Miscanthus go to pieces after the growing season is over. Except part or all of the central stalks may persist for some months, especially with the larger, more robust forms and species.

It holds up fairly well if I trim the stalks that fall over once in awhile during the winter. When it starts looking worse than good in late winter I set fire to the clumps that are out in the open. They burn right down to the crown and sprout in the Spring like n
Burning is more fun than whacking the stalks down and disposing of them. Sometimes after cutting the stalks down I spread them out and cover with woodchips.
I got the idea of burning them from the grass seed farmers in eastern Washington and Idaho. The burned fields produce more seeds the following year than the unpruned fields.
There are no seed heads on the above picture because the clumps are in partial shade. They're not all that attractive anyway.
othing happened.
The clumps spread slowly. I have four as large as the one shown.
In the picture below, the 'Giganteus' will be the first to go as I edit this over planted, confused area.
Mike

But what about miscanthus? sidebar on page 51 of the December 2013 Fine Gardening magazine calls it Miscanthus x giganteus, says it "appears to be a sterile triploid".

UPDATE: i know everyone is hanging on the edge of their seat.

I went with four 1 gallon M.s. condensatus from Joycreek. 20% off, so $8 a pop. Not so bad a price.

Nice to head up to the nursery and walk through the gardens and pick out my favorite. They had a couple in no irrigation, and partial irrigation zones. And they all looked pretty good. Fall foliage is amazing. Purple/red/green/straw.