Technical Abstract: Addressing the underlying causes of rangeland weed invasion is key to long-term, affordable control. Among the most important causes are insufficient competition from native species, often due to disturbance, and a lack of insects and diseases from invasive species’ native ranges. Restoration of slow-growing, competitive, native species can greatly reduce invasion. Effective restoration is challenging, however, particularly given changing environments. Biological control, the introduction of insects and diseases specialized on particular invaders, can also limit invasion in rangelands. Furthermore, restoration and biocontrol are likely to work well in combination, because they are both effective against the same fast-growing invasive species.