Do I have to dig in the boundary wire for the GARDENA Robotic Lawnmower?

No, the boundary wire can be laid on the ground and fixed in place using the pegs provided. After a few weeks the grass will grow over the wire. A good tip: to enable you to lay the wire as close to the ground as possible, the grass should be cut as short as possible before installation. If you are also planning to aerate your lawn, the wire should be buried about 5–20 cm deep in the ground.