Property developers across Northern Ireland are facing
a knotty problem that threatens the local wildlife and
has the potential to damage new buildings.
The culprit in question is a plant – Japanese knotweed.
It is described by environmental consultants at White
Young Green Ireland, as 'an ecological bully'.
The weed can cause extensive damage to buildings and is so
much of a threat to the environment that it is illegal to
cause it to spread in the wild.
It's such a problem to builders and developers that White
Young Green is running training courses to help the industry
get to grips with the invader. Dr Eleanor Ballard, senior
ecologist with the consultancy firm explained - "Japanese
knotweed was introduced by adventurous Victorian gardeners
who soon realised that it had a nasty side.
"It is an ecological bully that causes extensive damage to
buildings as it can grow through mortar and tarmac with ease.
It's a real scourge to the natural environment too - blocking
the sunlight from our native plants. If you cause it to spread
in the wild, you are breaking the law. We are advising developers
that it’s cheaper and less problematical to start dealing
with the plant as early as possible in the development process."
New Japanese Knotwood plants become visible in early
spring and emerge from the ground appearing red or purple
They grow rapidly during the summer to a height of
Their leaves are shaped like a shield with a small
pointed tip and are bright green in colour.
The stems are hollow with purple specks and the rhizome
(an underground stem) under the plant is thick, woody and
may have small red buds - each of which has the potential
to grow a new plant.
In winter, the Japanese Knotwood leaves die back, but the
dead stems persist and resemble bamboo-like canes. These are
often a good tell-tale sign that there is a knotweed problem
on a site.
Dr Ballard said the weed was difficult to kill off - "One
application of weed killer will not solve the problem and
we are working with a range of public and private sector organisations
to identify the plant on their sites and produce management
plans to assist in its removal.
"We've also introduced training courses to help developers
understand the risks that knotweed can cause to their new
buildings and development plans and we advise people working
on sites how to identify and control Japanese Knotweed."