I keep the skins on the ginger root and turmeric, but it's up to you. I do slice up the apple to remove the core and stem, but again leave the skin on the apple pieces. I have on occasion accidentally tossed the lemon into the juicer as well and it was fine but some lemon rinds do impart a slightly bitter taste so that's why I avoid it.A warning that turmeric stains yellow so clean it up sooner than later if it lands on something you don't want to turn yellow.
1/2inchfresh turmeric root
1/2inchfresh ginger root
2tablespoonsfresh lemon juice I add up to 1/4 cup depending on how sweet the apple is; sometimes I just toss a quarter slice of lemon with rind into the juicer.