Leaf colour: reading the season's last signal

Colour change is the tree's own weather report. Even, gradual colouring across the whole canopy is normal senescence — nothing to do but enjoy it. Colour that shows early, patchy or only on one side more often points to a root or watering problem from earlier in the season than to anything happening now. Either way, this is not the moment to intervene: let the leaves finish and drop in their own time, and note anything unusual in the journal for next spring's plan rather than acting on it today.