Broom Bloom Boom - Vancouver Island is under attack

Photograph of the Malahat on Vancouver Island and the explosive growth of the invasive plant broom.

See all that yellow?  That's Scotch broom, often just referred to as broom.  It is not native to North America, nor a lot of other places it grows without mitigation.  In New Zealand, it covers the distant hills, turning them yellow in the spring.  In much the same way, it has an aggressive foothold on the Island where the highways are embraced by mile upon mile of the invasive plant.

In the city of Akoara, broom and gorse have taken over the hillsides.

New Zealand has been dealing with the explosive growth of broom and its close relative, gorse, for years.  It has gotten so bad that the surrounding hills turn yellow in the spring.  It's not that bad on Vancouver Island, yet, but it is still early.  Soon, it will be everywhere.

It has a high oil content, so much so that there is talk of commercializing it to extract the oils from it.  The problem here is the high flamability of it - think dead cedar branches, only worse.  No part of the plant is edible, in fact it is toxic to humans.  Birds do, however, eat the seeds and aid in its dispersal.

It outcompetes native plants, replacing them and reducing biodiversity.  It also has the ability to fix nitrogen and use up the phosphorus in soil which greatly affects soil chemistry.  If you look at the broom plant closely, you will notice that its stems are green in colour.  The plant can grow year-round because of this.  

There are biological and chemical controls of Scotch broom, but they require action.  Nothing native to its introduced areas consumes the plant, but there are foreign moths and beetles that feed on the plant.  Sheep and goats will eat the seedlings and surpress growth.  This may help for local control but the its wide-spread nature makes this impractical.  The best way to irradicate the plant requires cutting it down and applying herbicides.  

Ascent has an excellent website on control of Scotch broom.  Click here to see it.

Thanks for reading.

Eric Svendsen     www.ericspix.com