Learn about plants that can invade the Okanagan

Many invasive plants almost impossible to eradicate once they get established.

die Steeves/Capital News Escaped garden plants such as purple loosestrife—invasive aliens—can destroy wetlands like this by choking out native plants and out-competing them for nutrients and water

die Steeves/Capital News Escaped garden plants such as purple loosestrife—invasive aliens—can destroy wetlands like this by choking out native plants and out-competing them for nutrients and water

I’ve always had a soft spot for the cheerful oxeye daisy with its simple white petals in a ray flower and a golden yellow centre, so it’s disappointing to see it is one of the 26 most invasive garden plants we should watch out for.

But, I’ve had lots of experience with pretty garden plants that have turned out to be almost impossible to eradicate once they got a toehold, like the Chinese lantern, with its masses of underground roots and the classic Lily of the Valley, which I never imagined would get away from me the way it did.

We spent weeks digging out an entire garden in which that sweetly-scented, lovely little English garden favourite simply took over, choking out every other plant and producing new ones from the tiniest fraction of a white root left behind.

So, I’m absolutely determined never to permit an invasive to stick its lily-white root in my garden soil again.

Such plants seem to literally jump out of the garden and take over adjacent wild areas, whether that’s the boulevard, a ditch or a wild spot nearby.

Remember how that single plant of Baby’s Breath along the road expanded in just a year or two into miles of rolling, smelly mounds of gray-white? Florists may love it for arrangements but it produces 10,000 seeds a plant which it can distribute over huge distances as the stalk breaks off and rolls away, dropping seeds everywhere it goes.

Alien invasives are still available at many nurseries, warns Evan Rafuse of the Invasive Species Council of B.C., who will be speaking on the topic at next week’s meeting of the Central Okanagan Naturalists Club. It’s Tues., Nov. 12 at 7 p.m. at the Evangel Church on Gordon Drive and everyone is welcome.

As a farmer, landscaper and biologist, he says consumers drive the demand for such invasive plants so nurseries aren’t likely to stop stocking them unless you stop asking for them.

The ISC is starting a certification program for nurseries that have agreed not to stock invasive plants, and we all have a vested interest in supporting them.

Once an invasive is established there are no known natural controls of its spread, outside its native habitat, so it easily becomes nearly impossible to control . It can cause considerable damage, choking out native plants, destroying rangelands and wildlife grazing areas and creating a monoculture that even insects shun.

He notes that in the past, people would bring favourite plants from their native lands, not realizing such aliens might overwhelm native vegetation—and today we’re paying the price.

Do your bit by not buying, selling or trading such plants, of which there are 500 in Canada. Many have deep roots, poison animals and produce millions of seeds spread in often-ingenuous ways.

For details of such plants, go to the website at: invasiveplantcouncilbc.ca

With a changing climate, such plants are now better able to become established in areas where they are not native, so a coastal plant is not necessarily only able to become invasive at the coast.

I’ve even noticed English ivy that’s gone nuts where it gets a bit more than the natural water here—and it is one of the 26 most-invasive garden plants.

Practising water conservation in your gardening efforts helps to prevent the spread of some invasives from other areas in this dry climate.

Water should also be a concern in this climate, and you’ve still got a week to submit your comments on what’s being proposed to update the century-old Water Act in B.C. with a Water Sustainability Act. For details, and to comment, go to: http://engage.gov.bc.ca/watersustainabilityact/the-proposal/

The devil will be in the details, which will be in the regulations created after the act gets to the legislation next spring, but if you don’t say your bit now, it’s tough to complain later.

Judie Steeves writes about outdoors issues for the Capital News.


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