This heavy (recycled) rubber strip is just what you need to separate different garden areas, like flower-bed and lawn. It’s 3 mm thick, and can be cut to any length you wish (you’ll need garden shears for this!). The rubber material is extra robust and durable: it’ll stand up for years against all weathers and maltreatment of other kinds like being trodden on, run over by the garden barrow etc. One thing, however: it’s not suitable for evening out differences in height between garden areas.