I am growing P. smallii over here in Georgia. Got it a couple of years ago at Home Depot, of all places! It has done so well for me!

P. digitalis is of course just the species version of 'Husker Red'. If you like the cultivar, I'd just stick with that.

This year I am trying Penstemon tenuis which a friend started from seed. It's still just a rosette in a pot right now.

Here is a picture of my P. smallii this morning (after the rain!):

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Nice photo...

Have you tried growing P. canescens? What growing conditions do your Penstemons prefer?

Mine seem to always reseed into the dryest parts of the garden but then our periodic droughts do them in. I have dry scree beds and regular flower beds and am debating where to put nursery bought plants or if growing from seed is smarter.

RJ

I have not tried P. canescens - but only because I've never come across it.

My P. smallii are growing in full sun in a bed next to the driveway. Because the driveway slopes down, this area gets a good bit of moisture from runoff (when we're not in a drought). The bed has pretty good soil because I raised the level of it about 6-8 inches when I landscaped the whole area. It reseeds a fair amount and I pop up most of the seedlings to give away or donate for the native plant society sales. My friend has it too and hers did not reseed.

The P. digitalis that I have are in a drier area and it seems to do fine. I put some 'Husker Red' up by the mailbox (with some other native plants) and that has done fine, but the deer occasionally nip a tip or two (not all of it).

I have a patch of "Gulf Coast Penstemon" (penstemon tenuis) that I started from seed someone passed on to me a few years ago. It reseeds a bit and is making a nice drift in my part shade border. It is very similar in color to the one pictured earlier in this thread. This year I am trying cutting it back to see if I can get more bloom out of it. Someone at a local nursery said that would work. Always before it bloomed well for a couple weeks in mid spring and then went to seed.

I have another I started from seed year before last. I ordered the seeds from Parks and think it was called "Rocky Mountain Penstemon" (penstemon strictus). The pictures they showed lead me to think it would be a very dark blue/purple. It finally is blooming this spring and is a fairly ordinary medium purple. It is planted in a sunnier location than my others but is a bit loose and bendy (if you know what I mean) and doesn't stand up straight and tall as I had expected.

I've read that most all penstemons prefer good drainage. I certainly have that - basically I grow in sand. However, the various different varieties of this plant seem to require different light levels. If I have a secret I guess it is to try to match what the plant needs to what part of my garden best suits.