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Invasive plants and horticulture

Most invasive plants has been introduced as ornamentals

Ornamental plants are part of our everyday life. They are decorating our gardens, parks, roadways, and we enjoy it. From producers to consumers, many people use them : nursery men, public departments responsible for plantations or green spaces, garden contractors, landscape architects, garden amateurs. Since the Victorian age, the horticultural sector is developping more and more.

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Photo : R. Roletschek

Unfortuntely, there are invasive plants among ornamentals. Most invasive plants have been introduced for the first time as ornementals. They have escaped from cultivation, botanical garden, private garden, parks and have invaded natural habitats. Lots of invasion have started this way. In Belgium, at least 80% of invasive plants included in the black list are ornamentals (see list of invasive plants).

For more information about invasive plants and the horticultural sector, clic here

 

They may escape from parks and gardens...

 
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Rockspray (Cotoneaster horizontalis) escaping from a garden...and colonising chalk grasslands (photos : M. Halford)

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The Himalayan baslam (Impatiens glandulifera) in a private garden...and along invaded riverbanks (photos : J. Guyon, S. Vanderhoeven)

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The rugosa rose (Rosa rugosa) planted along roadways...and in invaded coastal dunes (photos : M. Halford, E. Branquart)

Therefore man remains an important vector for spreading invasive species. All over the world, he transports them, plant them, spread them. This process is increased by globalisation and amplification of international trade exchange.

Did you know it ?

The Japanese knotweed (Fallopia japonica) has been introduced in The Netherlands in 1823. This plant became popular in Europe since 1847, receiving the gold medal of the most “interesting” plant of the year by the Horticulture and Agriculture Society. Since that time, the species has been planted in numerous garden and parks. It is now one of the most problematic invasive plant around the world. 

Photo : E. Delbart