How to Kill Ragweed

Pull the ragweed by hand. This is the most common method for ragweed control as these plants are easy to spot and pull. It is important that you pull the ragweed in late spring before they flower and develop a strong root system. If fully mature, a ragweed plant can produce more than 60,000 seeds during the flowering season.

Apply herbicide. RoundUp, Medallon, and Finale14SL are examples of herbicides used to kill ragweed. The best time to apply herbicide is mid-spring to early summer. This ensures the leaves of the ragweed are still relatively immature and more susceptible to the herbicide. The application of herbicides is not 100 percent effective as some species of ragweed have developed a tolerance to common weed killers.

Mow the affected area every two to three weeks. This is the preferred method in more populated areas and near delicate plants that limit the use of herbicides. Frequent mowing is necessary because ragweed plants are difficult to cut at the soil level and will regrow in two weeks. If more than 1/2 inch of a stem remains above ground, the ragweed plant could branch off into three or four full-sized stems.

Improve the soil by adding compost to open flower beds. The added nutrients will keep the soil healthy and prevent ragweed plants from establishing. Cultivate the soil regularly using a hoe.