@Skathm It's always a tough call deciding whether or not to use an herbicide. When you have an existing, highly invasive plant type you basically only have two options: 1) using an herbicide prior to installation to eradicate invasive plantings 2)relegate yourself to a lifetime of maintenance battling the invasive weeds. For this project we did use an herbicide to eradicate the existing bermuda grass prior to installation. Now that this meadow has filled in it does not require herbicides or other pesticides, uses less water, requires little-no fertilizer, and is beautiful. Ultimately the choice to use or not use herbicides is a personal choice and it will depend on your willingness to use an chemical on your yard (even if it is just a means to an end), your aesthetic tolerances (are you ok with having weeds in your meadow? - some people are) and also how much time and expense you are willing to dedicate toward future ongoing maintenance. Hope this helps!