Translation:I need to wash mushrooms and potatoes.
Sorry, but I was listening to this song when I got this sentence... :) https://www.youtube.com/watch?v=lmuseX1ujpM - Mrs. Potato Head
potato, Singular, or kartoshki
Карто́шка is a mass noun, it's not used in plural.
To "clean" should also be accepted here, as it is for other sentences
Why not "I must wash mushrooms and potatoes"?