Once invasive species populations have been managed sufficiently that establishing competitive vegetation is possible, a cover crop of native grasses or perennials can be a highly effective technique for combating invasive regeneration. The cover crop may or may not be part of the intended long-term plant community for the site, but its primary purpose is to utilize open space and light, making those resources less available to invasive regrowth.  The reduced regrowth in turn reduces the amount of investment that is needed to maintain the site.