Researchers used 1,200 tonnes of soil and rubble to build a 10m-long, 30m-wide embankment to test their theory.
The Scottish Crop Research Institute (SCRI) site in Dundee aims to "tackle the life-threatening dangers posed by landslips using plants", said a representative.
Slopes beside Britain's road and rail networks are expensive to build and maintain, he said. Prolonged rainfall in recent years has meant that slopes have blocked roads due to landslides or rapid erosion.
Researchers tested soil and compost treatments to see how well plants established in recycled soils treated with compost.
"With more plants the soil should be more stable as the roots will act like reinforcing rods," said SCRI scientist Dr Paul Hallett.