Weed Killer Roundup

The experince I have had with weed killers is that they last too long and suppress daffodil growth. I cannot use RoundUp, although the manufacturer says it does not have lone lasting effect, I live right by a creek that absorbs all of the chemicals I might put in the soil. I am concerned with the extreme loss of habitat for salmon and other live creatures that inhabit the stream. We have decreased water flow due to less rainfall and more people syphoning off water for their own uses. I feel responsible for the environment and therefore use no chemicals. If I get a daffodil that looks ill I burn it. My daffodils are beautiful and look healthy here.
Nancy R. Wilson