A Yellow Leaf Is a Symptom, Not a Diagnosis: The Notes I Check Before Changing Anything — Implementation Notes From GrowBook

I ran into this while using GrowBook on my own plants, then had to decide what the app should do.

One yellow leaf can mean old growth, too much water, too little water, root trouble, a cold draft or nothing worth panicking about. The colour alone does not tell me which one.

What GrowBook does

Before changing fertilizer, moving the pot and watering again on the same afternoon, I check the recent history. When was it watered? Did I repot it? Has it moved closer to a window? Did several leaves change together, or only the oldest one?

The boundary I kept

A plant journal does not diagnose the problem for me. It slows down the urge to make five changes at once. GrowBook keeps photos and care events on one timeline, which makes that check easier.

One yellow leaf now earns one note and a pause, not an afternoon of random treatment.

GrowBook on Google Play: https://play.google.com/store/apps/details?id=com.yuntai.growbook