Ask Mr. Smarty Plants

Let's start at the beginning. You probably heard about Habiturf. Read the linked article through for instructions on planting it. It is recommended for seeding only on well-prepared soil. Another article on Native Lawns discuss the research that went into the development of this grass. Neither article mentions the precise portions of the three grass seeds that are combined, but your numbers sound like a fair approximation of the proportions.

From Native American Seed, you can see Native Sun Turfgrass, which is composed of 80% buffalograss and 20% blue grama seeds, no curly mesquite.

We heard that those who purchased native grass turf squares frequently found them pre-infested with nutgrass, not a desirable addition to the combination. We don't think making your own sod is really practical, and don't know a source for sod forms. Also, in your situation, you probably don't have enough sun in your side yard for the grasses to flourish; they need 5 to 6 hours of sun a day.

On the subject of viability of the 2-year old seeds, we could find very little hard information. This USDA Forest Service website on Hilaria belangeri (Curly mesquite grass) has only one short comment on the seeds:

"Curlymesquite has good soil binding qualities and grows on most soils, so it has potential as a rehabilitation species. Commercial seed is hard to get, so mulching with hay is the most economical seed source. Also, curlymesquite is not drought resistant, so revegetated sites need sufficient irrigation." The article also mentioned that the plant is shade intolerant and seedling vigor is "medium," whatever that means.

We had about the same luck trying to find out much about the seeds of Bouteloua gracilis (Blue grama). All we found on the USDA Forest Service on this plant about seeding was: "Blue grama is readily established from seed, but depends more on vegetative reproduction."

We did find an article on Maintaining Grass Seed Viability from Oregon State University. In summary, we do not have a magic incantation for getting those two grasses to grow; you might contact the original source for your seed to see what they recommend.