Tar Like Substance on Part of Neighbour’s Lawn

Question

Because I use my lawnmower to cut this lawn, I am afraid of the wheels of the lawnmower transferring the substance onto my lawn. What is it and how can it be treated?

Answer 1

This is likely black slime mold. While it is unsightly, it will not harm the lawn. This opportunistic fungus normally develops in overly wet conditions but usually goes away on its own once drier conditions prevail. Black slime mold can be prevented by ensuring the lawn and areas near the lawn have adequate drainage and no standing water.