Tuesday, May 17, 2011

Cascara Buckthorn: An Oregon Native Tree

One of the trees I’ve used in my native landscaping is the Cascara tree, or Cascara Buckthorn (Rhamnus purshiana).  Native along North America’s west coast from southern BC to central California, the Cascara’s dried bark was used by Native and immigrant Americans for over a century as a laxative.  According to Wikipedia, “it was the principal ingredient in many commercial, over-the-counter laxatives in North American pharmacies until 9 May 2002.” 
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As interesting as that is, the only home remedies I hope to get from my four Cascara trees are a little shade and some natural habitat.
Three of my trees I purchased through Friends of Trees, and they’re placed along the street in the front parking strip.  The fourth is in the yard near the SW corner of the house.  They were all a decent size when we planted them, so I’m hoping it won’t be too long before they start providing some shade to the front of our west-facing house.  Cascaras are not large trees, so they will never shade the whole house.  I’m just hoping for some late afternoon screening when the sun is lower in the sky.
When I’m out and about, I always watch for plants that I have in my yard, to see if I can spot them “in the wild”.  The only time I’ve seen a Cascara in its natural setting was over at the coast, in a wooded area near the beach.
3496611674_326dc3b215_bCascara leaves are a nice, dark green and fairly thick, too.  The tiny spring flowers seem to attract lots of insect pollinators.  Small berries start out red and turn black as they ripen.  Cascara is one of the plants recommended by Audubon to provide food for Western Bluebirds, and like the berries of the Pacific Madrone, I’m told they’re a favorite of Cedar Waxwings and other berry-eating birds.
The leaves turn a pretty bronze color in the fall.  Not as spectacular as some of the yellows and reds we see, but still nice.  There’s a good series of pictures (provided by Oregon State University), showing the habit of the trees in various seasons, starting here.  Use the “next” link at the top right to move through the pictures.
Even with a small yard, if you just provide a little bit of habitat – and you look close enough – you can attract some native wildlife…
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