Plant This: Gulf Coast penstemon colors the shade garden

I’m singing the praises of Gulf Coast penstemon (Penstemon tenuis) today. It’s in peak bloom in my garden and throughout Austin. Spires of lavender, bell-shaped flowers stand about 1 to 1-1/2 feet high in the shade or morning-sun garden and look especially nice underplanted with purple oxalis and ‘Diamond Frost’ euphorbia (an annual) and paired with columbine. Add pigeonberry (Rivina humilis) to the mix for low-growing summer and fall color when the penstemon and columbines are spent.

You’re going to want a lot of these to make an impact, so don’t bother with onesies or twosies at the nursery. Buy 7 or 11 in 4-inch pots and plant them in a curvy sweeping swath. They don’t grow very wide, being rather tall and narrow for an understory plant, so I space them about a foot apart.

They can also be grown from seed if you don’t require instant gratification. In fact they seed out fairly readily on their own, particularly in damper areas. In my own well-mulched garden I get fewer volunteers, maybe only one or two each spring.

Bees love them. You’ll often spot just their legs and rear end sticking out of a flower bell.

After the flowers go to seed, I leave the seedheads standing all summer in my garden to maximize the chances for self-seeding. If you don’t want volunteers, you can cut back the seedheads. In late winter, if they’re still standing, I cut off the seedheads and watch as the winter rosettes of leaves begin plumping up for the next spring show.

Note: My Plant This posts are written primarily for gardeners in central Texas. The plants I recommend are ones I’ve grown myself and have direct experience with. I wish I could provide more information about how these plants might perform in other parts of the country, but gardening knowledge is local. Consider checking your local online gardening forums to see if a particular plant might work in your region.

All material © 2006-2011 by Pam Penick for Digging. Unauthorized reproduction prohibited.

15 Responses

  1. Greggo says:

    Nice planting plan for the season. I used this plant when I lived in San Antonio. I planted it in an east exposure in heavy high pH soils amended with Gardenville soil mix and of course way too mulch cedar mulch derived from the developer (it was a new home). I was surprised it did so well in that area. Love the scale of the leaves as compared to other Penstemons. I currently am growing P. “Elfin Pink” and “Red Rocks”.

  2. Nice pics of a very pretty plant! It pairs well with the oxalis. I picked up one of these at your go-go swap a couple of weeks ago and I love it! I will definitely be putting more of these in my garden.

  3. linda scott says:

    Beautiful…hmmm…I’m in a hilly area of Driftwood, and I have tons of buds on my roses, etc., but nothing has popped out fully yet other than wildflowers. My trumpet vine is just leafing out now. I think I’m at a higher elevation…I even got some cold damage on plant tips the other night..on non-tropicals! My white Lady Banks is only halfway has lots of buds..the one’s that are protected are blooming. I guess they all knew it wasn’t quite safe to come out, but I expect this week everything will pop.

  4. Juliet says:

    Love it! Always looking to add more color to my morning sun garden. Where did you originally get yours? I work at the Natural Gardener but haven’t seen this type of penstemon yet this year…

    Hi, Juliet. I probably got it at Barton Springs Nursery or Natural Gardener originally. I would be very surprised if NG didn’t carry it. But if you don’t mind shopping the competition, try BSN. —Pam

  5. Katie Myers says:

    Love that yours are also decorated with the oak catkins…like everything in my yard!

    I appreciate your blog so much for planting advice (in this case the bit about how many to plant) — those kinds of tips are always helpful to me. Does this guy like sharp drainage like a lot of the other penstemons? Also does it do ok in dry shade or does it prefer more moisture?

    You can see that I’m not into staging my photos, Katie. :-) Gulf Coast penstemon does better with a little more moisture than sun-loving penstemons, I think. It will take poor drainage but doesn’t require boggy soil. My garden is generally pretty dry. —Pam

  6. More Penstemons! More! Thanks for showing a Penstemon that likes to grow in shade! Everyone could benefit from more Penstemons in their garden. I have not tried P. tenuis before, but I may get some seed and give them a try.

  7. katzien says:

    Wait a minute….you do a plant swap?? Well, no wonder you keep it secret…you might well be overrun with swappers. ;-) I also have a too shaded side garden, so I’ll give this a try. Thanks for continuing, season after season, to awe and inspire us with your photos and stories.

    Thanks, Katzien. The Austin garden bloggers get together on a regular basis and often swap plants. We’ll all be growing the same plants eventually. :-) —Pam

  8. Mamaholt says:

    This is JUST the plant I need!!! Yea, Pamolicious to the rescue again!

  9. Darla says:

    It is very delicate looking…does look nice in larger groupings.

  10. Lona says:

    How lovely. It looks so beautiful against the purple leaves of your oxalis.

  11. Lisa at Greenbow says:

    hmmmm something for shade. I wonder if there is a penstimen that will grow and flower like this here. I will look for one.

  12. Scott says:

    Just lovely…I’ll definitely keep an eye open for this one!

  13. Chookie says:

    What an airy little plant! Well, not so little as all that. Lovely!

  14. I have Husker’s Red Penstemon but have not tried Gulf Coast. Always looking for blooms in shady areas — I’ll have to keep my eye out for this one. Think it will live in DFW area, or is it not cold hardy?

    Various online sources say it’s hardy to zone 7, Toni, so it should be worth giving it a try in Dallas. —Pam

  15. I’m living and volunteering at Anahuac NWR which is on the upper Texas Coast. We used to have a lot of Gulf Coast Penstemon. It came from a friend’s garden in League City where thousands of babies came up each year. We thought the 18′ surge of seawater and 5 days of being under salt water, a gift of Ike, had killed it all but three hardy plants are blooming in our butterfly garden. It is one tough plant and is the only penstemon that can stand our wet clay.