Posted on | October 1, 2014 | 3 Comments
It’s encouraging to see residents of greater Los Angeles cutting back on lawn irrigation and/or switching to less thirsty ground-covers. But there has been an unintended consequence. Civic-minded homeowners have been under-watering — or not watering — their trees. While deciduous trees register the stress palpably enough that many homeowners are alerted to the need to irrigate, most evergreens can’t wilt. Rather, their leaves furl and their needles droop. Formerly turgid and healthy limbs become brittle and vulnerable to boring insects and the diseases that the bugs too often carry. Stress a big tree enough and it becomes prone to what monitors of our urban canopies call “tree failure” (an interesting term for an outcome that is almost never the tree’s fault, but that of those managing it). A treeless Los Angeles would be a harsh, hot and bleak place. To prevent that from happening the Urban Forest Council has issued this brochure. Click here for more about common causes of tree failure, and here, here and here for an excellent three-part guide to planting trees from horticulturist and Rancho Santa Ana Botanic Garden fellow Barbara Eisenstein.