what turns a dappled willow's leaves brown?

Question

we had the rain from the one of the tropical storm this summer , so i thought maybe it was from all the rain we have had this summer. the plant doesn't seem to be doing it now. It is growing ok. i just wanted to find out why it happened.

Answer 1

A lack of water will usually cause brown leaves.

Answer 2

A shock like a heat wave, or not enough water. Zap the leaves can drop. A healthy established tree will usually recove well when condition return to 'normal' soon enugh.