Return to the Arizona Gardening Forum | Post a Follow-Up

Volunteer penstemon and non-volunteers

Posted by psuperb1 9 Tucson (My Page) on
Tue, Oct 4, 11 at 16:16

Last October I planted Penstemon superbus and P. parryi x superbus from a plant sale. Both bloomed in spring and I let them set seed. I cut both to "rosette" and cut back on summer water but while the P. superbus (Ps) did well, the P. parryi x superbus (Ppxs) looks dead.

With our end-of-monsoon rains, I noticed four seedlings around the "dead" Ppxs and only one seedling near the Ps.

Assuming seedlings should be about 12 inches apart, I am going to have to transplant a couple of the seedlings. At what stage would it be best to try to move them?

Should I pull out the dead-looking Ppxs or wait until next spring to see if it "comes back"?

In addition to self-seeding germinations, I also saved some seed and scattered it nearby. Should I be watering that area to try to coax out some non-volunteers? Does a 2-gallon springling can of water each evening seem like enough?


Follow-Up Postings:

RE: Volunteer penstemon and non-volunteers

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 :)

RE: Volunteer penstemon and non-volunteers

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,

RE: Volunteer penstemon and non-volunteers

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.

RE: Volunteer penstemon and non-volunteers

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.

RE: Volunteer penstemon and non-volunteers

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!

 o Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

    If you are a member, please log in.

    If you aren't yet a member, join now!

Return to the Arizona Gardening Forum

Information about Posting

  • You must be logged in to post a message. Once you are logged in, a posting window will appear at the bottom of the messages. If you are not a member, please register for an account.
  • Please review our Rules of Play before posting.
  • Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review your post, make changes and upload photos.
  • After posting your message, you may need to refresh the forum page in order to see it.
  • Before posting copyrighted material, please read about Copyright and Fair Use.
  • We have a strict no-advertising policy!
  • If you would like to practice posting or uploading photos, please visit our Test forum.
  • If you need assistance, please Contact Us and we will be happy to help.

Learn more about in-text links on this page here