P. pinifolius does well here, and we get plenty cold.
In general, I find the Penstemons not to be very long lived as compared to other perennials, and they like to wander a bit and some are very promiscuous, so there's always a few surprises, some of which are quite nice
Anyway--the thing that does them in is wetness in the cold weather when they are dormant. Here we get snow in the winter which isn't rain and isn't actually wet until it melts...
I'd always heard that lavender doesn't tolerate humidity...if you can grow lavender Lynda, then your friend might wanna check out the dwarf lavenders that HCG offers--I love them!
Here's a pic of a section of my driveway rockpile around the end of May--it is such mayhem, I call it the fruitloop effect
contains many of the plants mentioned...
The reds, Helianthus 'Ben Ledi' at the left (turned into quite a shrub!)...P. pinifolius 'Compacta' at the right by the car
There are several different dianthus and penstemon varieties in there, salvias lower left all volunteer bee-seedlings, tanecetum is the silvery stuff at the base in the center, and creeping thymes, dwarf lavenders not blooming quite yet...
here you can see one behind the campanula
I don't think anyone has mentioned that yet, but the are several decent campanulas to try.
This thing is a cute little mat-form of Ziziphora clinopodioides
and just to make the point that a person can do anything they want in their rock garden--a mini rose