Step 1 Beginning at 1 side of garden bed, dig a hole 600mm deep. Insert trench mesh and pack firmly with excavated soil. Bend mesh over to create arch (you will need 2 people), mark the position on ground and dig another 600mm hole. Secure other end of mesh. Repeat the process with a second length of mesh, overlapping the first piece at the top.
Step 2 Where 2 lengths of mesh cross over, secure in several places using tie-wire.
Step 3 Beneath centre of arch, excavate 100mm of soil where steppers will go. Using power saw, cut sleeper into three 600mm lengths. Position lengths between the 2 paved areas.
STEP 4 Infill area between steppers with soil mix, then rake to level. Fill remaining garden section with soil mix.
Step 5 Compact soil between steppers using back of the rake, then spread a mulch of decorative pebbles over top. Tread down to firm up area.