Made a video of the backyard garden for the first time as a story.
Just out of curiosity, measured the resistance of eggplants and tomato plants. When it is between the edge of a egg plant leaf and stem, the resistance value is about 2MOhm.
Old leaf doesn’t have moisture and it looks like the equivalent resistance of the old leaf is very high (i.e. open circuit). Small and young leaf have less resistance. Depending on the nutrition of the plant, the resistance seems to change.
I can use the tomato as a current limiting resistor to turn on a LED.