The first time I weighed a pot I felt slightly ridiculous. There I was at the kitchen counter at eleven at night with a Philodendron gloriosum on a $24 digital scale, writing 1,438 g in a notebook like some kind of horticultural accountant. The plant looked unimpressed. The cat looked concerned.
Six months later I had stopped killing things. Not because I had finally absorbed some mystical feel for moisture — I have a perfectly normal sense of touch — but because the scale told me, unambiguously, what the substrate held and what it had given up. A pot is a closed system with one variable that matters most: water mass. Schedules guess at it. Moisture meters approximate it. A scale measures it.