You could run into problems if you get Roundup in the pond. I' d worry about the Roundup killing your pond vegetation but check your instructions as to the fish. The only time that I' ve had a problem with it was when there was puddles of water near the trees that I was spraying. I lost a few trees when the puddles soaked into the soil. As for the apple trees; only let the spray touch mature bark.

Dan O.