Question
We live in Tacoma, Wash and for the first time in 15 years since we bought our house we have large brownish mushrooms growing in our front yard. It is not just 1 or 2 but I picked probably close to 24-30 of them this weekend. What caused this all of a sudden? Is there something our lawn is lacking like nitrogen or something? Please email me back to let me know what to do.
Thank You
Liz

Answer
Liz:

You live in an area of the country perfectly suited to mushrooms.  I do not know why they have suddenly appeared.  I can only hazard a guess that conditions were perfect this summer/fall.

Since they do not, in themselves, harm grass, I would not worry.  However, if their appearance indicates a strong fungal activity below the soil surface, you may consider a program to encourage grass over fungi.

The fungal hyphae (root system) may be aggressive and pervasive, preventing grass roots from receiving water and nutrients.

I would aerate the lawn area, fertilize a few times a year and overseed with the type of turf you have or desire.

Fungicides will not be too effective against a large colony of muchrooms.  However, specific fungal diseases may be treated to good effect.

Have the muchrooms identified, no easy task for some of these, and consider a fungicide if recommended for that genus and species.

Only a few fungi will require addition of nitrogen to overcome the effects.

Hope this helps.  Best wishes.