Hello. We&#39;re sorry to read about your disappointment with Roundup Weed &amp; Grass Killer4 with Concentrate and appreciate your feedback. <br /><br />To get the best results when making an application of Roundup Weed &amp; Grass Killer4 Concentrate, we suggest doing so when the weeds are actively growing and your air temperatures are between 60 and 85 degrees. It can take up to 2 weeks for complete control. Also, to get the best results, the plant leaves must be thoroughly and uniformly covered with the spray solution.<br /><br />We want you to be confident in our products. For this reason, we offer a product guarantee. If for any reason you, the consumer, are not satisfied with the results after using this product, you are entitled to get your money back. Limitations apply. At your earliest convenience, please reach out to us at 866-324-2647 if we can further assist.