i used to germinate seed for a production nursery. i don't remember the procedure for penstemon but i've noticed them growing wild in every colour in washes, so it can't be that hard :)

germination can be tricky in arizona, i think because of opportunistic, moisture seeking molds and insects. one method i use is to germinate in a sealed container, eg. tupperware. use a layer or perlite or coarse sand with the water table below it so that seeds are not in direct contact with water (after an initial overnight soak).

if mold starts, i add a drop of hydrogen peroxide (or perhaps diluted bleach) and then rinse after ~20 minutes.

the real problem i have is with gnats stripping seedlings of root cilia. the only solutions to this i know of are to use a sealed area for seedlings (which takes diligence and is a strike against the plants due to air circulation) cold-pressed neem (would need to order) or a pyrethrin or other toxic insecticide :/ (i'm not sure if BTI works on gnats).

not having grown penstemon in my own garden (though there are plenty of them out there!) in the nursery, we grew bedding in plug flats, eg. the seedling would be transferred after ~3 weeks from a 1" cell. naturally, if i were concerned about the survival, i'd probably transplant after ~3 sets of proper leaves or so.

if anyone is interested, i have a batch of neem seedlings started, i'll probably offer some next spring :)

I love penstemons too and always have quite a few around the garden. If your seedlings were mine, I would leave them as-is and let them do their thing. The best looking penstemons seem to be those which are allowed to pop up when and where they like to.

That being said, if you insist on transplanting them, now is a pretty good time so that they can settle in over the winter and then burst into growth in the spring. Be sure to give them a very thorough drink when you plant them, and try to dig up as many roots as possible.

Let us know what you do and how it works out.
Take care,
Grant

I clip the seed stalks off when they are starting to ripen and shove them bottom up in a 5-gallon bucket until the seeds fall off. Then in the fall I scatter them liberally where I hope to grow them.

Sometimes it works, usually it doesn't.

Thanks for the three responses. Something I can use in each of them.

Lazygardens, I know what you mean, "Sometimes it works, usually it doesn't." Seems to me that if the rain doesn't initiate germination, no amount of tap water will.

Grant, you are right. I tried transplanting one. Now I'm down to three seedlings. I decided better to leave others in place and see what happens. My Midwest tendency is to overwater but I'm trying to lengthen watering interval since this is Arizona.

Keep us posted. :) Most of my P. eatonii look dreadful all summer long, but they do perk up right around now, and they are, so there's hope for spring. Scattering seed around now should encourage some spring seedlings too. I do love penstemons, although the key is, as you said, to give them just enough water to survive.

Good luck--updates are encouraged!
Grant