There are some things that can be done to prevent weed problems before they get overwhelming. Certain types of weeds can indicate problems with your soil which if corrected may eliminate or reduce those types of weeds. Visit http://oregonbd.org/weeds-2/
When weeds are small scrape the soil with an action hoe, stirrup hoe, or Winged Weeder. This cuts the weeds off right at the soil level either killing or weakening the weed. Many will not grow back. This method also makes it less likely that you will be bringing buried weed seeds to the soil surface where they will begin to grow.
To prevent seeds from germinating (pre emergent) use corn gluten meal. Corn gluten meal is leftover from corn syrup processing, looks like corn meal, and has been shown to reduce weeds over time. Corn gluten meal works best if used in Spring when the daffodils are blooming and in fall when the weather is beginning to cool.
For more weed control ideas: http://www.hometalk.com/149466/organic-weed-control