Best Understory Palms for PNW?

[BeyondTheGarden]

As my garden gets bigger, I find myself wanting to fill dead space with understory palms.  So far I've got a few needles, a sable minor, and a few Chamaerops humilis (maybe not exactly "understory" but I use it for the same function).  They're all quite small, most are brand new to me.  I've also got a few Arenga engleri's and Chamaedorea microspadix, but those are marginal where I live and will eventually need protection or perish, and I don't really include them in my list of dependable palms here.  

I'm looking for palms that stay around human-height and form a hedge, a ground-level backdrop of wild fronds.  Our summers are so mild, I think everything I listed grows at snail pace.  What is the quickest growing, most robust palm that serves this function, up in this area?  

Thanks. 

[amh]

Trachycarpus wagnerianus might work, it will get tall, but not as tall, and while they are not palms, there are some hardy cycads.

Edited June 16, 2021 by amh

[Trustandi]

I don't think there are many selection for understory palms for our area maybe trachycarpus nanus or princeps perhaps use palm-like plants like yucca or cordylines?

[amh]

51 minutes ago, Trustandi said:

I don't think there are many selection for understory palms for our area maybe trachycarpus nanus or princeps perhaps use palm-like plants like yucca or cordylines?

How cold hardy are the nanus and princeps, I'd like to grow these myself, but I see them rated zone9.

[Trustandi]

 @amhI think nanus is 7b and princeps is 8a. I have a nanus x wagnerianus but it is still in the pot. I usually use the hardiness trial from trebrown nursery for my palm benchmark.  Yorkshire Kris from YouTube also has good information video growing different trachycarpus. UK has similar climate to our PNW area. 

 http://www.trebrown.com/documents/climate/palmhardinesstrials.php

 

[Chester B]

Not too many options - I'd say Chamaedorea radicalis/microspadix and needle palms.  I use a lot of the big evergreen ferns, they have a similar look and the Soft caress mahonias look very palm like.

[BeyondTheGarden]

I do love my mahonias.  I'm surprised the big box stores don't carry them. I have to go to a local nursery to find them.