Sean
Hathaway - Swansea's Knotweed Officer - and a town under
seige |
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Interviewer:
Can you tell
me a bit about your job?
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Sean:
My name is Sean
Hathaway and I'm employed by the Planning Department of the City
and County of Swansea as the Knotweed officer. I've been doing the
job for 2 years.
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| Interviewer:
Why
are invasive plants like Knotweed harmful? |
Sean:
It's widely recognized by all environmental bodies world wide that
after habitat destruction the greatest threat to species is the
spread of invasive, exotic and alien plants. In this country, Japanese
Knotweed is probably the worse of a number of examples of such a
plant.
It can also cause physical damage. It can grow through tarmac and
knock over walls and fences. We've actually had it inside several
houses in Swansea. It's very costly and time consuming to treat,
usually with chemicals, although they're not suitable for many sensitive
locations, e.g., those that have a conservation value.
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| Interviewer:
How does
Knotweed reproduce? |
Sean:
All
of the plants in this country have been DNA tested and it's been proved
that they're all genetically identical to the original plants that
first came into the country back in the early 1800s. So in fact what
we've got is probably the largest female in the world - all the plants
are the same as the original female. |
| Interviewer:
How
is it spread then ? |
Sean:
In
this country it's mainly spread by pieces of the root and stem being
spread about either through movement of soil or flowing down rivers
and landing on a beach or a piece of river bank downstream and growing
into new plants. |
| Interviewer:
Why
is Japanese Knotweed so successful? |
Sean:
It grows and
spreads very very quickly. It can out compete our native vegetation
and so you can end up with a monoculture of Knotweed and nothing
else. Our own species that should be there cannot compete and once
amongst a growth of Knotweed, it's very dark and shady and there's
not enough light for other plants to grow.
You
only need a very very small piece of a stem or a rhizome system
to grow into a new plant. It can grow in any habitat. We've got
it in the sand dunes here in Swansea - I've even seen it growing
on the beach. It can grow on the edge of woodlands, in dry soil,
wet soil, virtually any type of soil.
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| Interviewer:
What
can be done about it? |
Sean:
If people want
to get rid of it , it's actually classed as a waste because it's
so invasive. There are very few waste tips licensed to take it.
If you have it in your garden you must do something though, as if
you leave it, the problem will only get worse and it will spread
There
are a number of chemical that people can buy, e.g., from a Garden
Centre. They should buy the chemical for strong perennial weeds,
and they will need to be very diligent in their spraying - probably
a couple of times a year for a number of years. One spray won't
kill it off, it will almost certainly come back the same season
or the next.
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|
Interviewer:
How do
you feel personally about Japanese Knotweed, having worked with
it for so long?
Interviewer:
Thanks
very much Sean.
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Sean:
Well I think
it's a great plant really. It does cause many many problems, but
you have to respect it - the speed that it grows - the damage it
can do. It's
a very interesting plant and working with it for the last couple
of years, I've met a lot of interesting people and written a number
of interesting scientific papers. I've helped a lot of people deal
with the problem and other organizations in other areas have followed
our lead in tackling their Knotweed problems.
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- Interview with Sean Hathaway