Invasive plants - what's the big deal?

Whether you are interested in the environment or not, the problems caused by non-native invasive plants affect us all. For a start, they cost us billions of pounds to put right - £2 billion every single year in Britain alone, according to the Government. Their spread is recognised as one of the greatest threats to the economic well-being of the planet.

Then there’s the structural damage to roads, houses and flood defences. Many invasive plants can re-grow from just a tiny fragment of plant matter left in the soil or water meaning it is often impossible to clear an area of unwanted plants in one go – it can take years to put right. Damage to your prospects of selling your home, clogged waterways which can increase flood risks, reduced crop yields and skin-burning sap are a few other ways in which invasive plants invade our lives.

As far as nature is concerned, invasive plants often form monocultures, taking over an area so that they are the only plant growing there. Rhododendron (Rhododendron ponticum) poisons the soil around it so that other plants cannot grow. Other invasive plants grow very quickly, preventing light reaching slower-growing or shorter plants, and so causing those less aggressive plants to die off. By decreasing plant diversity, the creation of a monoculture can also remove habitats for animals.

To make things worse, non-native invasive plants are often unpalatable to native herbivores like invertebrates. Monocultures of non-native invasive plants can, therefore, lead to reduced food availability in an area as well as reduced habitat. In waterbodies, invasive plants can spread over the surface of the water reducing light and oxygen levels below which can be damaging for both plants and animals.

 

“... the cost of ignoring the problem [of non-native invasive species] will be almost incalculable – lost agricultural production, lost trade opportunities, spoiled crops, human disease and allergies, clogged catchments, reduced water availability, threatened rural livelihoods, disrupted ecosystem services and species extinctions.”
Extract from The Global Invasive Species Programme (Protecting plants and plant habitats from invasive alien species).

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Can I help?

The simple fact is that more than 60% of invasive plants in the UK are garden escapees. If we as a nation of gardeners have (inadvertently) caused much of the problem, then the good news is that we can solve much of the problem by the choices we make.

Most invasive species are still available for sale, with many garden centres, pet shops, aquarists, DIY stores and supermarkets across the country continuing to sell damaging species. The Government is currently considering whether or not to ban the sale of some of the most damaging plants, but you can do your bit now: tell store managers that you don’t want to see non-native invasive plants on sale and don’t buy them. Click here for more information on ways you can help.

Even if you are a responsible gardener or fish-keeper and dispose of problem plants safely – by composting or burning them or using a municipal garden waste collection – they may be carried into the wild by the wind or by birds and other animals outside of your control. That’s why we think avoiding non-native invasive plants in the first place is the most effective choice.

The bottom line:

NEVER release ANY garden or aquarium plants into the wild - don't tip them down land drains, don’t dump them in the countryside, don’t throw them into your normal waste bin. Compost or burn them or use your local council garden waste collection.

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