I Spy in the Sea to Sky!

I Spy in the Sea to Sky!
I Spy in the Sea to Sky!

We decided to give you all an easier I Spy this week, with a pesky weed holding a name as misleading as its beauty!

Butterfly Bush is a tall, deciduous shrub, producing bunches of long, cone-shaped flowers. These blooms can come in orange, blue, red, pink, purple or even white! Its leaves are long, thin and slightly velvety on the underside, drooping from the stems in a lazy, wind-catching motion.

This nasty invasive spreads rapidly, producing up to 40,000 seeds per plant and reproducing rhizomatously from root fragments, cut stems or broken branches. Its lightweight seeds are most commonly carried to new regions through wind patterns, water currents and human transportation. This includes hitching a ride on motor vehicles, construction equipment, mountain bikes or even tucked among the treads of hiking boots! Not only is this relentless weed an infesting pro, but its seeds can remain viable in soils for up to 4 years, waiting patiently for just the right conditions to incite germination.

Although butterflies and other pollinators are attracted to this boastful bush, its role in a foreign ecosystem provides very little support. Small insects may seek nectar from the weed, but in displacing more productive, native plants, many insect’s reproductive cycles become disrupted. Once established, Butterfly Bush uses its deep taproot to suck up vast amounts of nitrogen and phosphorous from the surrounding soils, making it even more difficult for native vegetation to thrive. This can be especially problematic for sensitive environmental conditions, such as forest regrowth from timber harvest, or wildfires.

In terms of management approaches, Butterfly Bush is best tackled using an integrated approach. Young infestations can be mechanically removed by cutting off the bulk of the bush and subsequently digging up the plant’s taproot, enveloping it in a tight plastic bag to prevent regeneration. Larger, more mature populations sometimes require chemical treatments, cutting off the base of the stems and applying herbicides to the open wound. This technique is most effective when active sites are revisited and given a follow-up treatment! Another, less effective but far more charming, control method involves goats grazing on Butterfly Bush, the goal being population depletion, rather than eradication.

This terrible weed is categorized as “contain” under SSISC’s Species Priority List for Squamish, “eradicate” for Whistler, and “prevent” for the Pemberton region. That means we have to take extra care to prevent it from spreading into new territories and work diligently to get rid of it once and for all! If you think you’ve spotted Butterfly Bush, report it here or email us at info@ssisc.ca.

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