Answer: Round Up is a contact vegetation killer so even the drift from the spray can harm desireable plants. If your goldenrod was exposed to the drift of Round Up, anything it touched it probably killed. The good new is that Round Up does not move in the soil so the roots of your plant are probably alright. You'll need to prune away the dead portions of your plant and wait for new growth to emerge. It's very important to read and follow label directions when you use a weed killer. Some, such as Round Up, will kill everything in sight!
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