Thanks for the info. I just want to do it right before I fill the pond. I plan on supporting it with a well. I need to remove some more dirt and I havent been able to work on it for awhile (thats why there are so many weeds.) After the dirt work is done I plan on tilling in soda ash.

So if I disc the area before I fill is that enough to get rid of the weeds or do I need to kill them first? And then how do I keep them from coming back? Also, should I use rock or sand to keep the weeds down. Again, I just want to do it right before I fill. Thanks