Answer: Now that you have the stiltgrass removed from your pachysandra beds you can apply a pre-emergent herbicide such as Preen, or one made from corn gluten meal. Corn gluten is sold under several brand names (WOW! is one brand). Look for corn gluten based herbicides at your local garden center or in the organic section of gardening catalogs. Pre-emergent herbicides will stop weed seeds from germinating but will not harm other plants such as your pachysandra.
Best wishes with your garden!
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