Question
Hi. I live in the Mojave desert in southern CA. I have a fremont cottonwood on a graywater system and it's doing great, but I wonder how much water they take for optimal growth. Any idea? Thanks

Answer
Trees need about 1 inch of water per week--place a pan under the tree and turn the sprinkler on and when the pan has 1 inch of water in it stop. If you have not done so mulch around the tree with not more than 3 inches deep of organic mulch not piled up on the trunk. This will help hold moisture around the roots.