I spent a year squeezing leaves to measure their water content. Here's what I learned

Tomás I. Fuenzalida, Author provided

How do you tell if your plants need water? Recently, I asked this question of a group of about 40 biologists at the Australian National University.

Most of them said they would stick their fingers into the soil. If you want to be more scientific about it, most horticulturalists would argue it is best to weigh the pot to determine how much water it contains.