Question: When should I be watering trees in fall?
It's not enough to know why you should be watering trees in fall (the subject of the prior FAQ); you also need to know when to do it -- and when not to do it....
- Stop watering trees, both evergreen and deciduous, throughout early autumn, until the time when the leaves of the deciduous trees fall. This will allow both evergreen and deciduous trees to enter a transitional phase, not unlike the "hardening off" undergone by nursery plants in spring. What you're trying to avoid here is causing spurts of new growth that won't be winter-hardy.
- In late autumn, after the deciduous trees have dropped their leaves, give both evergreen and deciduous trees a deep watering. This should be done before the ground freezes.