In my lawn there is an arc shaped stripe that is brown. In the past a giant white ball shaped mushroom appeared over night at the end of this stripe. This year a giant black one appeared. Is this a lawn fungus that needs to be treated? The attached picture shows a much smaller chunk of the original black mushroom. Thank you.
Kenton County Kentucky
Based on you photo here are two possibilities for your issue.
1) A large tree was once in that space and when it was removed the roots were close to the surface. As they decompose the spore of mushrooms emerge. If that is the case they will naturally decline and you can manually remove as you see them.
2) There is a fungus known as Fairy Rings. This fungus is naturally occurring from the soil it seems to affect our cool season grasses. Treatment by aeration and adding seed and making sure that area is fertilized with lawn fertilizers each fall. This fertilization ensure deeper root development of the grass and they emerge next spring as stronger plants. If after a couple seasons there is no improvement, there are fungicides that can be applied. We can help you with that if needed. There are always safety exposure issues to consider when using any pesticide.
Thanks and have a great fall.