What are ballast plants

In the period between 1500 and 1900 ballast was used to stabilize sailing ships and help them to navigate when they were carrying little cargo. The ballast was comprised of stones, sand and earth shoveled onboard in the many harbours of Europe. Back in Norway the ballast was dumped either in the sea or on land.

In the ballast were seeds. When the ballast was dumped on land the seeds could germinate and put down roots. In this way new types of plant came to Norway. These are called ballast plants. More than a hundred new types have come to Norway in this way.