Lemons are fairly easy to root. Congratulations!

For the 'store-bought' leaf-and-stem mandarins, they can be difficult to root. Often they are too dried out to root even though they look quite green, but that's not always the case. Make sure you maintain humidity. I have had success grafting them but not rooting. I've tried several times. Let us know what happens.

I have a grafted tree from a stem and leaf mandarin. I've had more luck grafting versus trying to root cuttings, but I wish you luck. Keep us updated!