This poster refers to a victory garden. Victory gardens were homemade gardens planted by American citizens during World War I and World War II. The goal was to use fruits and vegetables from these gardens to ensure that there is enough food for soldiers overseas. The expectation was that whoever planted these victory gardens would contribute their harvest to the war effort.
In this poster then, the intended message is that anyone who grows a victory garden is having a direct, positive effect on the military. This is evident from the soldier in the background stating that " I see were fighting the war together."
