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June 28, 2015 - To help trees survive drought conditions, keep trees as the first priority for outdoor watering. Lawns can come back if they go brown, but trees take decades to grow and never return once they die. Slowly deep water trees as needed early in the morning or after sunset. Trees are a vital resource that clean the air, provide homes for the wildlife and improve our neighborhoods. 
Source: DWR

how to save your trees during drought