Plum Grove, TX has a population of 449 and is the 20,215th largest city in the United States. The population density is 120 per sq mi which is 23% higher than the Texas average and 32% higher than the national average. The median age in Plum Grove is 42 which is approximately 22% higher than the Texas average of 34. In Plum Grove, 56% of the population over 15 years of age are married, 91% speak English and 8% speak Spanish. 71% of Plum Grove residents were born in Texas, 22% were born out of state, 3% were born outside of the United States and 4% were foreign born.