I planted plugs of blue gramma and buffalo grass about 3-4 years ago and it's starting to be invaded by weeds. I pulled the weeds and spread out some new soil over the remaining blue gramma and buffalo grass. Im not sure how I get it to grow? do the seeds just go on TOP of the soil and i have to water every day? how long do I have to water? I read about burning to invigorate the native grasses...will this help?

thanks