The purpose of this trial was to determine if weed populations in pastures could be changed or reduced by varying the timing of mowing throughout the late spring and summer growing periods without the use of herbicides. Weeds can become a problem when they interfere with light penetration to the forage plant leaves, if nutrients intended for the forage plants are used, or they take water or growing space from the forage plants. This can directly influence the yield, quality, and productivity of the field. Treatments in this four year study consisted of: (1) Control (no mowing), (2) June mowing, (3) July mowing, (4) August mowing, (5) September mowing, (6) June/August mowing, (7) July/September mowing, and (8) monthly mowings in June/July/August/September. Each treatment was replicated four times. Forage and weed dry matter samples were taken at the beginning of each month and each plot was visually rated for broadleaf weed pressure contained at the time of sampling. A scale of 0-9 was used (0 meaning 0% weeds present to a 9, meaning 90% weeds present). Results for 2019 indicate that mowing in June had similar results as the control. June mowing produced 4.1 tons of forage and 688 pounds of weeds, compared to the control which resulted in 4 tons of forages and 565 pounds of weeds on a dry matter basis. The average visual rating was 4.1 for June and 3.0 for control plots respectively.  Monthly mowing did reduce weeds, but also reduced total forage production to only 2.4 tons of dry matter. In 2019, the July treatment resulted in the lowest quantity of weeds with 522.0 pounds of weeds per acre and 4.0 tons of forages. The July/September treatment had only eight more pounds of weeds but reduced total forage production by 912 pounds per acre.