This summer, we took our first trip to Sweden for a “family roots” trip to visit my great-grandmother's village.  What does this have to do with backyard gardening in Solano County?  Read on . . .  

As we drove up the center of the country, I was charmed by the pastoral scenery: rolling pastures and red houses interspersed with forest.  But what really caught my eye was the lupine growing alongside the road.  Tall, vigorous, glorious lupine ranging in color from deep purple and blue to lightest lavender.  It was spectacular!  Every bend in the road brought an even more beautiful patch of lupine than the one before it.  It seemed every stand of lupine deserved its own photo shoot.

But then I noticed that the lupine tended to grow in disturbed areas along the road, for example, where road grading had recently occurred.  And a little voice inside my head wondered whether something so vigorous, no matter how beautiful, might be a little suspicious.  And I started to think about invasive species in California and how people brought interesting and pretty ornamental plants to their gardens that eventually spread uncontrollably).  (I'm thinking of you, oxalis, Scotch broom, and pampas grass.)

Sure enough, when we asked our hosts about the lupine, they explained the controversy over the plant and whether it should be eradicated.  While I'm not sure which species we saw, I believe it may have been Lupinus polyphyllus, which is known to inhabit environmentally disturbed areas such as roadsides, railway embankments and near pastures.  It can outcompete native vegetation and is poisonous due to its toxic alkaloid content and can harm sheep, cattle, and other species.  The lupine was introduced intentionally as an ornamental plant, but was later also used for other purposes such as soil improvement and stabilization.  It is recorded as a “garden escape” in Sweden as early as 1870.  (For a description of a similar ecological crisis with a different species of lupine in Iceland, please refer to Jennifer Dodini's blog, published on June 26, 2017, entitled, “Trip Musings-Iceland's Ecological Controversy” at http://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=24610.)

Lupinus polyphyllus isn't just an issue in Scandinavia, but here in the United States too.  For example, it has been found growing in Denali National Park and other areas of Alaska and there are concerns it is hybridizing with other native lupine species.

So what does this mean for our Solano County gardens?  We should be aware of the plants we purchase and their potential for being invasive.  PlantRight, discussed below, defines invasive plants as ones that “are non-native, can spread on their own, and cause or are likely to cause environmental or economic harm.” Fortunately, we have several good resources to reference when questions arise. 

• The California Invasive Plant Council's (Cal-IPC) mission “is to protect California's lands and waters from ecologically-damaging invasive plants through science, education and policy.”  It provides an inventory of plants that threaten the state's natural areas. The list includes plants that currently cause damage in California (invasive plants) as well as "Watch" plants that are a high risk of becoming invasive in California.  http://www.cal-ipc.org
• PlantRight works with California's nursery industry to keep invasive ornamental plants out of the landscape “and to promote the sale of exclusively non-invasive alternatives.” PlantRight provides a list of invasive species and an alternative list of recommended plants.  https://plantright.org

On a side note, I noticed that a particular pink rose was used throughout the countryside and in the cities as a hedge rose.  I don't know what type of rose it is, but the blossoms were wonderfully fragrant.  When I asked for the plant's name, my hosts couldn't translate the name into English, but described picking the “berries” for jam.  This puzzled me for a bit – the plant certainly looked like a rose, which don't have berries – until I realized that they likely picked the rose hips for jelly!