Answer: In many cases it is possible to control annual weeds by cutting them off short and then mulching with several inches of organic mulch such as shredded bark. If this is done very early in the season, the weeds are smothered. Raking the mulch periodically and topping it up as needed to maintain a steady two to three inch layer will prevent blown-in seeds from germinating as well. The side benefits to this approach include moderated soil temperature and reduced need for watering, as well as a steady soil feeding as the mulch breaks down.
If perennial weeds are a problem, the above approach will help to wear down their root reserves. As they surface through the mulch, apply glyphosate as indicated on the label instructions. Be careful not to allow it to contact other desirable plants as it will harm them. Also be sure to allow the foliage to fully wither and die before removing it, this ensures that the chemical has fully translocated to the roots where it acts to kill the weed.
In some cases where there are many perennial weeds, you may want to use a layer of cardboard or several sheets of newspaper beneath the mulch. This extra layer helps exclude light and further enhances the smothering effect of the mulch. If you use newspaper, soak it in water first (use a large bucket, a wheelbarrow or a kiddie wading pool), and work in small sections at a time.
Good luck with your weeding!
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