Gardening is the preferred pastime of many, but do you know exactly what you are growing in your lovingly curated garden?
Because chances are, much of the beauty of your garden comes from the varying flowering plants that you have bought from agricultural exhibitions and a mixed bag of stores that sell small attractive plants for your home garden.
But, what you probably didn’t know is that many of those attractively colourful plant lives are non-native invasives and therefore are aggressive exotic plants that thrive in our growing conditions, and with no natural enemies, have nothing to check their rapid spread.
In unknowingly introducing these invasive alien species (IAS), which are often brought in for their ornamental value, or accidentally, by hitchhiking with other products, you are paving the way for grave environmental costs to your patch of land.
The Convention of Biological Diversity (CBD) – “Invasive Alien Species (IAS) are species whose introduction and/or spread outside their natural past or present distribution threatens biological diversity.”
Invasive plants often crowd out native vegetation, and reduce biological diversity, can change how entire ecosystems function, and pose a threat to endangered species.
Speaking with the President of the Young Zoologists’ Association Mega Ganeshan and also staunch MAS sustainability champion at Linea Aqua about why we must be concerned with what’s growing in our backyard, she said: “Invasives are quick to establish, and they grow rapidly once established. They are long flowering, and are aggressive competitors.” She added: “There are many attractive exotics that have the potential of being invasives but we haven’t been able to prove which ones are threats as yet.”
Mega also spoke of the effect of invasive plants in large ecosystems in the island – like Bundala National Park – which is a flat land which should essentially have shrubs and smaller growth, but is swarming with Kalapu Andara (in English – Algarroba bean), which is an erosion control tree, currently being removed due to it being invasive to the environment in Bundala.
She also mentioned Ulex – Ulex europaeus (gorse) – an invasive shrub deemed as one of the most invasive species in the world, which happens to be a beautiful yellow flower. She said: “This is but one example of the varying degrees of invasive plant life we have in our lands, and it’s important to be aware of them.”
Buddhika Jayalath, an urban organic agriculture consultant spoke further about the invasive plants we have in our spaces that pass themselves off as food.
“There are several species which pass themselves off as something else which are either invasive and/or harmful to us,” he said, adding also that “some examples are Korean Gotu Kola (Asiatic Pennywort), which is an invasive plant that is extremely difficult to be rid of and is very much similar looking to Gotu Kola.”
“There’s also the ‘Red Lady’ papaya, which has overtaken the growth of local papaya, which has a far greater nutritional value to that of the high yielding Mexican variety.”
Buddhika also mentioned that it is very important to grow your own produce in your own home; and invasive plants which drain the nutrient components of your garden and mess with the natural soil compositions often result in thwarting many efforts, and thereby discouraging people to continue to grow their own produce.
He added: “You need not have a large patch of land to be able to do it, and you need not purchase expensive fertilisers. You can simply make it at home, and it is extremely rewarding.”
Here’s a list of potted plants that can be grown in your home: Komarika, Talabo, Heen-Talabo, Goda Manel , Hatawariya, Gal-Pahi, Gal-Demata, Kudalu, Gal-Ambala, Begonia, Bim-Hak-Ambala, Kapparaweliya, Wal-Kapparawalliya, Iraweriya, Maha Hedaya, Kuda Hedaya, Wana-Raja, Itu-Raja, Fox-Tail, Kaha, Hinguru-Piyali, Inguru, and Tebu.
How to identify IAS
As for what we include in our home garden, there are two documents published by the Ministry of Mahaweli Development and Environment in order to help in identifying IAS. Invasive plants or animals can be identified using the provided pictorial guide.
What you should do
· Prevention is not always possible. Therefore, the next level of management is mechanical, chemical, or biological.
· Mechanical controls include pulling, digging, and/or cutting, which should be your first line of defence. Mostly useful for new or small infestations, these methods cause minimal environmental impact and only require basic gardening tools.
· Chemical controls involve the use of herbicides. However, it is important to inform yourself of the potential health risks prior to the use of such products.
· Biological control is the use of natural enemies and this maybe your best choice as natural enemies for many of the more troublesome invasive species are available.
By Dimithri Wijesinghe
Pics from http://www.iassrilanka.lk/index.php/en/