A plant is so high on the most-unwanted list, it's an all-out war to keep it under control.
This tall drink of water produces gorgeous pinkish-purple flowers perfumed with a sweet
scent. But this alluring beauty brings some serious fire-power to the battlefield with
seed pods that explode at the slightest touch. This is Himalayan balsam.
Hi, I’m Tasha the Amazon and you’re watching Floralogic. Today we’re talking about a
pretty-in-pink beauty that is bent on world domination.
Policeman’s helmet, bobby tops, gnome’s hatstand, depending on where you are, you
might know it as any of these adorable nicknames. But don’t be fooled by its cutesie headwear-inspired
aliases: This ruthless invader is here to take over.
Impatiens glandulifera belongs to the balsaminaceae family and the genus impatiens, also known
as “touch-me-nots”. These plants get their name from the Latin
word for “impatient” thanks to their aggressive seed dispersal. And impatient they are! One
slight touch and the ripe Himalayan balsam pod explodes firing seeds up to 7 meters away!
That would be like if a palm tree could shoot its coconuts across a football field.
Himalayan balsam gets its name from its region of origin, the foothills of the Himalayas
from north-west Pakistan to northern India. But this plant is hellbent on world domination
and has since invasively spread all across the Northern hemisphere.
Once famed for its stunning ornamental beauty, Himalayan balsam is now infamous for hijacking
space, light and nutrients from native plants. Basically: Worst houseguests ever!
And Himalayan balsam doesn’t mess around when it comes to moving in on native species’
turf. Each individual, which can grow to around 3 meters tall, can produce up to 800 seeds
in its short life. When mature, the seed capsules of these space invaders explosively roll up
at the slightest touch. This dramatic display fires their seeds far and wide, ensuring their
survival… and choking out their native neighbours in the process.
Now let’s see those seed grenades again in super slow mo!
In areas with established himalayan balsam populations, and with all those projectiles
flying through the air, up to 30,000 seeds can collect in a single square meter. Native
species don’t stand much of a chance against that onslaught. The seeds of the Himalayan
balsam can survive up to two years too after it’s been ejected, so you know it's ready
to play the long-game. One of the main ways Himalayan balsam is spread
far and wide is by anthropochory, which is just a fancy way of saying good ol’ fashioned
human beings. And you wonder why we people can’t have nice things?
Thanks to their good looks and pleasant perfume, people just can’t seem to resist adding
these trespassers to their gardens. And they’re not just attractive to humans. Himalayan balsam
produces large amounts of sweet nectar and becomes a regular watering hole for bees.
Drawing pollinators away from native species is just another one-two punch these invaders
employ to ensure their success. But this plant isn’t just a danger to native
species… It may even be responsible for accelerated riverbank erosion. After pushing
out native perennials, the annual Himalayan balsam dies off in winter leaving the riverbanks
it loves so well exposed to the elements and prime for erosion.
These meddlesome beauties are the definition of hit it and quit it!
Efforts are being made in particularly hard-hit areas to combat unwanted Himalayan balsam.
In the UK, where this plant has been a pest for 150 years, self-proclaimed “balsam bashers”
organize bashing parties to wipe out invasive populations.
Groups of volunteers get together to yank them out by the roots. Destroying invaders
in hand-to-root combat sounds like my kind of fun!
A project headed by the Centre for Agricultural Bioscience International in the UK has also
levelled-up the battle against Himalayan balsam. After 8 years of research, a rust fungus that
infects the stems and leaves was chosen as the most biological weapon against this invasive
species. The fungus doesn’t impact native species and has already started the slow process
of eradicating this beautiful killer. If you live anywhere across the Northern hemisphere,
you’re likely to encounter Himalayan balsam, either in the wild or in your neighbour’s
front garden. While making the pods explode may sound like
a great way to startle your loved ones, to stop the spread, it's recommended to not let
them go to seed. And definitely don’t trade them at your next seed exchange!
So what should we talk about next? Let us know in the comments and don’t forget to
subscribe for new episodes every week. Thanks for watching. See ya!