Natural Rock Gardens at Horsepasture Mountain

One of the big thrills of the day was the discovery of a Pacific giant salamander dining on a succulent slug along the road on the way up.

Yesterday (October 15), Sabine Dutoit, Loren Russell, and I took a special visitor from Sweden to Horsepasture Mountain. Peter Korn is touring the West, speaking to many of the NARGS chapters. He was in town to speak to our chapter the night before. Peter has an extraordinary 5-acre botanic garden and nursery near Gothenberg, Sweden (click here to check out his website), where he grows an enormous collection of plants from around the world, including a great many Pacific Northwest natives. He wanted to see these plants in the wild and hopefully collect some seed. I figured Horsepasture Mountain would be an ideal spot to give him a taste of the Western Cascades. The hike is fairly quick, and the cliffs are small enough to allow one to access the front without a difficult climb up a talus slope like many cliffs I have explored.

The view from the summit of Horsepasture is a real bonus, and we were very lucky that clouds drifting above us when we arrived at the trailhead disappeared quickly. By the time we reached the top, we had a great view of many of the High Cascade peaks as well as nearby mountains including Lowder, Olallie, Tidbits, and Castle Rock. The closest peak to Horsepasture is O’Leary Mountain. There was a great display of fiery vine maples on its shrubby slopes. The sun was appreciated on this chilly autumn day. About the only thing left in bloom was tiny Polygonum cascadense and some reblooming skyrocket (Ipomopsis aggregata). It is biennial or monocarpic (dying after setting seed), so somewhat like an annual, it is opportunistic, blooming as long as it can get moisture.

Outstanding fall color could be seen on nearby O’Leary Mountain.

Rush pussytoes (Antennaria luzuloides) forms tiny plantlets in the leaf axils that fall off and root this time of year.

The little plantlets on rush pussytoes (Antennaria luzuloides) were just starting to fall off. I collected a few to root to try, once again, to see if I could grow this in my rock garden. This is a really interesting plant. It reproduces by seed, like most composites, but also by small rosettes tucked into the leaf axils of non-flowering stems. I’ve spent a while studying this population—one of only two I know of in the Western Cascades. It appears to me that only larger, presumably older plants sport flowers. Small plants bear only non-flowering stems. As the plants get larger, they appear to have more flowering stems. The largest plants have mostly flowering stems, with only a few creating plantlets. It makes sense to me that young plants reproduce asexually as it requires less energy. Older, stronger plants can invest the energy it takes to create flowers and seeds. In the long run, sexual propagation, with all the variety it produces, is better for the population than thousands of clones. While its flowers are dull white, like most pussytoes, the cobwebby white hairs that cover this species give the foliage a beautiful silvery cast.

Saxifraga bronchialis, S. cespitosa, and Penstemon rupicola fill every crevice of the north-facing side of the summit cliff.

I had hopes that we could find something that was new and exciting for Peter. That turned out to be very difficult indeed. Apparently, Polemonium carneum is a common garden plant in Sweden (why isn’t it here?), Penstemon cardwellii is practically a weed in his garden, and he has lots of Penstemon rupicola as well. He recognized all the saxifrages on Horsepasture: bronchialis, cespitosa, rufidula, and ferruginea. All grow in his garden. He grows lots of skyrocket, but since there are no hummingbirds in Sweden, they didn’t set seed, so we managed to find a little seed left to replenish his garden. He said he grows something like 16 species of paintbrush (Castilleja species)—but not our beautiful Castilleja rupicola. Finally, something special we could show him! There was still a good amount of seed left in the capsules. I hope he is able to grow it successfully. More people are having success with these semiparasitic species by merely tossing the seeds into the garden in the appropriate spot to mimic their habitat. But I don’t know of anyone growing C. rupicola, my favorite species. If anyone can grow it, he’s the one.

2 Responses to “Natural Rock Gardens at Horsepasture Mountain”

  • I really appreciate the botanical details you give on this site. I am particularly fond of subalpine and alpine plants as well as natural rock gardens. I have a lot to learn, and will be visiting your blog again.

    That giant salamander is a gorgeous specimen! (I am a biologist and studied amphibians in grad school)

  • Hi Ivan,
    I checked out your Wild Pacific Northwest website ( Excellent site! I hope other people will check it out as well. I’m glad so many naturalists are putting their observations on the web and sharing their knowledge. We can all learn so much from each other.

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