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Catclaw mimosa (Mimosa laxiflora) is a native, perennial half-size brush, which invades short grasslands, interferes with cattle grazing and reduces productivity. This study was conducted to evaluate vegetation changes after the application of Grasland 20P at rates of 0 and 1.5 kg i.a./ha to control high infestations of catclaw mimosa in a short grassland at Cananea, Sonora, Mexico. Local information regarding how soon forage production increases will last after bush control does not exist. Tebuthiuron was hand applied on triplicated 20 by 30 m plots during May of 2005. Plots were arranged on a randomized complete block design. Data was analyzed by ANOVA. Plots remained excluded from cattle grazing from 2005 to 2014. Brush and grass density of main species blue grama (Bouteloua gracilis), hairy grama (B. hirsuta) and sidoats grama (B. curtipendula) were compared. There were 6,560 plants/ha of catclaw mimosa in 2005, 95.5% of which were controlled by the end of 2007, but 2,085 new young plants/ha were back in the plots by the summer of 2014. This represents 31.8% of the original brush density populations. Plant density of main grass species significantly (P<0.05) increased from 1.7 to 2.9 plants/m² on herbicide treated plots, and was very similar (P>0.05) over time in the controls. Grass basal cover was 6.7 to 9.5% greater (P<0.05) on herbicide treated plots as compared with the untreated checks. Although total forage production has been 590 to 1,025 kg D.M./ha greater (P<0.05) during all years on herbicide treated plots, forage increases differences tend to be less dramatic over time. Annual forage production in the controls varied from 215 to 387 kg D.M./ha during the study period. Total forage production increases on herbicide treated plots during the last five years is about half of the production obtained during the first five years following herbicide application.