It says self pollinating so a second tree is not needed. Only one i have is a meyers lemon and can confirm it is self pollinating.
4" pot is small. Citrus must be the new rage cause even walmart sells meyers lemon and various citrus in larger pots, big enuff to fruit.
Besides myers lemon i would look for satsuma citrus. Its one of the cold hardiest. It still needs protection but it takes cold better than other varieties.
1
