Tuesday, July 19, 2011

Living fossil

In yesterday’s post I wrote about a surprising encounter in Brookings, Oregon with Chilean rhubarb, Gunnera tinctoria, also known as “dinosaur food” because of its primeval look. On our explorations of the beaches around Brookings we encountered another category of plants that are equally reminiscent of the age of dinosaurs: horsetail rushes, also known as snake grass or puzzle grass.

In the banks adjoining the creeks that flow into the ocean, the horsetail rushes (Equisetum) are often the dominant species. Scouring rush (Equisetum hyemale) is a well-known ornamental and frequently sold in nurseries and garden centers. Native to moist forests and stream banks throughout the temperate regions of North America and Eurasia (and naturalized in Australia and New Zealand), it can easily become invasive if not controlled. I love its minimalistic, archaic look and have one growing in a container next in our backyard. I was excited to find one growing in the wild.

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Scouring rush (Equisetum hyemale)

Giant horsetail (Equisetum telmateia var. braunii) is even bigger. The largest Equisetum species outside the tropics, it can grow to 7 or 8 feet. The ones we saw were in the 3-4 foot range, growing in dense stands. The stems have numerous branches which grow in tight whorls. The result is a highly architectural look that would be a great addition to any pond or bog garden as long as there is some form of containment. Left unchecked, giant horsetail can easily take over. It is on many invasive-species lists and apparently is difficult to eradicate because of its deep roots (according to Wikipedia, giant horsetail has been “observed to penetrate 4 meters [12 ft.] into wet clay soil, spreading laterally in multiple layers”).

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Giant horsetail (Equisetum telmateia var. braunii)
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The coloration of the stems can be quite spectacular
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Close-up of branches radiating outward from the stem

As is the case with running bamboo, planting any species of Equisetum in your garden requires rigorous checks to ensure that no strays escape from the designated area. The easiest solution is to plant them in a container where it’s much easier to keep an eye out for runaway rhizomes.

This is not a plant for the faint-of-heart (or gardeners who prefer a hands-off approach), but if you have the necessary discipline Equisetum adds a unique, almost otherworldly flair to many landscaping styles, especially exotic and contemporary gardens.

More posts from our trip to Southern Oregon:

3 comments:

  1. Really impressive! I'm tempted to try and find some of the giant horsetail, but I really don't need another plant that requires special care to overwinter. I'll stick with the scouring rush. :-)

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  2. Equisetum in a container can look stunning :) I'm a fan myself and kept one in a pot for years before deciding to let it go, it only did well for a little while before it started to look scruffy. A giant one sounds promising!

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  3. I love the architectural form of horsetail!

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