black marks on gray plaster

crystal clear

New member
Sep 30, 2010
We just plastered a pool gray and something from a nearby tree seems to have fallen off, sort of small berry maybe? and stained the new plaster with little dark black streaks. Has anyone else run into this problem? And if so, any solutions to removing the stain?

Melt In The Sun

TFP Expert
LifeTime Supporter
Oct 29, 2009
Tucson, AZ
I'm guessing mulberries? Those things are such a pain! Like teapot said, chlorine will remove the stains if that is indeed what they are.


Are you certain it isn't black dye from the plaster? Was it there when they finished, or did they just appear?

I have seen poorly mixed plaster trowel out with black streaks before, when it does not fully blend in the hopper and comes out the hose with dry pockets of color that gets troweled. Hopefully it is organic and will go away, but you may want to double check in case you need to call the PB/plasterer.

Other Threads of Interest