I am new here and to gardening in general.
I have an old (~30-40 yrs) wisteria tree that blooms very nicely right now. My concern is how much should I water it during spring and summer. Where I live (San Francisco area), it doesn't rain at all from April till October, and every website I read suggest watering "only during prolonged dry spells". Well, 6 months sounds like a prolonged time to me, so I need a better advice, please. Last time it rained here was about 3 weeks ago and I haven't watered the tree since that.
The tree has a trunk about 6 inch in diameter.