Using the Sun to Kill Weeds

Last year, for the second year in a row, I spent a significant amount of time on my knees hand-pulling common ragweed (Ambrosia artemisiifolia) from the ground, with the end result being sore knees and hand cramping and words that I do not use in public. I did that early in the season because if it is allowed to develop seeds, ragweed can disperse 30,000 to 60,000 seeds per plant. Because the seeds are small and lightweight they can be spread by wind, water, birds, small critters, and humans. 

Ragweed produces a prolific amount of pollen and is the main cause of hay fever from late summer through autumn (https://my.clevelandclinic.org/health/diseases/ragweed-allergy). Many people attribute hay fever symptoms to goldenrods since they bloom at the same time. However, the pollen from goldenrod is not dispersed into the air by wind. The only way to develop allergy symptoms from goldenrod requires physical contact with the plant (https://www.webmd.com/allergies/ragweed-allergy). Photos of the ragweed plant can be found at https://www1.maine.gov/dacf/php/gotpests/weeds/index.htm.