Muhlenbergia filipes is Purple Muhly, and is hardy to about 10ðF, so you're right at the cold end of its hardiness zone. If you mulch the plant well, and site it in the warmest part of your garden, you will probably be able to grow it.

Pink Muhly is Muhlenbergia capillaris, and it's hardy to much colder zones.

They both can be grown in full sun to partial shade. Cloud cover during winter makes no difference to either. They are dormant during winter, and don't need sun.

Thanks Donn, is there a difference between the two of them, other than the color? Maybe I could incorporate both, but I'm not sure what the difference is between the two of them . Maybe the color?

I believe it's the Purple Muhly I'd like to get my hands on. You mentioned mulching them in the winter. I read somewhere that I shouldn't mulch them. Is that safe? If so, can you recommend to me how I should mulch them or what the care process would be?

I appreciate any help you can offer. Thanks again.

The biggest difference is winter hardiness. Otherwise, they are about the same size, and have the same characteristics of habit and bloom. I can tell which is which from the bloom, but unless you look at them side-by-side, you probably couldn't. Pink is more pink, while Purple is magenta.

Ornamental grasses shouldn't have their crowns covered with mulch during their growing season, but when they're dormant, it can be helpful. During at least the first two winters, you would be wise to cut the grass back before the coldest season comes, and cover the crowns with several inches of coarse mulch, like wood chips. As soon as the coldest season has passed, uncover the crowns. If you have a very wet cold season, uncover them. I assume you don't have reliable snow cover, so this method of mulching tender grasses gives them good insulation.

Donn, thanks for this information. I'm pretty new to ornamental grasses and I'd like to incorporate a few at home.

I'm a bit intimidated with growing the Pink Muhly in a Zone 8a environment, so maybe I'll go with the Pink instead. I spotted a photo online. Can you please let me know if it looks like the Pink Muhly to you (colorwise)? I've noticed that the names are used interchangeably for the plants online for some reason:

There are also several images of what looks to be the same plant on this page: http://www.discoverlife.org/mp/20q?search=Muhlenbergia

The plant looks purple to me, but they're stating that it is Pink Muhly.

Here is a link that might be useful: Additional Pink Muhly Photos

Everyone sees colors differently, and computer monitors represent them differently, but the picture you posted is definitely Pink Muhly ( M. capillaris).

Okay, thank you Don for this information, I appreciate it.

Kendra are you located in the PNW? If so, I'd reconsider the pink muhly -- it simply hates our winters (far too wet). And not nearly hot enough here in summer. The few plants I've seen growing here are seldom able to bloom before cold weather hits.

If you want a pink flowered grass, I'd consider Pennisetum orientale 'Karely Rose'. Not the same type of inflorescense - a 'brush' rather than a 'cloud' - but a similar good strong color and a reliable performer in the PNW.