Blue Grass, IA has a population of 1,563 and is the 12,459th largest city in the United States. The population density is 536 per sq mi which is 881% higher than the Iowa average and 492% higher than the national average. The median age in Blue Grass is 44 which is approximately 15% higher than the Iowa average of 38. In Blue Grass, 66% of the population over 15 years of age are married, 98% speak English and 2% speak Spanish. 72% of Blue Grass residents were born in Iowa, 27% were born out of state, 0% were born outside of the United States and 1% were foreign born.