Pine straw is lightweight mulch made from the needles of pine trees. This slightly acidic mulch is one of the best for smothering grass and controlling erosion. Pine straw is a safe choice for wooden homes, because it does not attract termites. Although pine needles are less prone to slipping out of place than other mulches, it can still spread across your lawn. If pine mulch is accidentally clipped with a mower, the results are usually scattered all over your lawn. Keeping pine needles in place is a simple matter of keeping your mower out of your flower beds.
A border made of rocks, paving stones, old tires or even a mow strip can serve as a buffer zone between your mower and your flower bed. Borders can be visually pleasing while keeping even the most haphazard lawn mower from clipping your flower bed. Thicker borders will also help keep spreading grass, such as Bermuda, from creeping into your flower bed from the lawn. Borders require periodic maintenance, but this may be limited to edging and cutting grass runners with a spade. Another way to create a border is to remove the sod between the edge of your lawn and your flower bed. This creates an almost demilitarized zone between your flower bed and your lawn that even the most haphazard mower operator can't miss.
Although a raised bed is often constructed to keep wildlife out of a vegetable patch, it may be used to keep the lawn mower out of your pine straw as well. A raised bed may be made from landscaping timbers, for example, around the foundation of a home or be freestanding in the yard.
Place pine straw in areas where the mower won't be used, such as the median in between two driveways, the area between your front walk and your home or an Island between two sidewalks. If the mower is unlikely to be used in the area directly around the median, it is less likely to come in contact with the pine straw itself.