Drought Tolerant Landscaping, Grass Area
After remaining one certain area for the fertile soil, there should be another area for the grass.
This is actually optional and it can be ignored particularly if there are already spaces for many green plants.
The grass itself is actually functioned just like other plants; it is to keep the water.
But since it looks neater mainly if you cut it off regularly, the grass just makes your backyard garden look more beautiful.