This time of year, I get inundated with calls about dying Incense Cedars, Coast Redwoods, Manzanitas and Pacific Madrones. Assuming that these trees are healthy, they are just doing their normal summer thing. Mid-summer is shedding time for a lot of evergreens, both conifers, and broad leafed trees as well. The place to look is the tips! The terminal ends of the foilage tells the story. If you see bright growth on the ends of the limbs uniformly throughout the canopy, you probably don’t have too much to worry about. After a big push of growth earlier in the year the dead brown/tan color really stands out and it grabs your eye, especially when viewed from beneath the canopy. The way to look is from the outside! If you see many dead tips on the ends of the branches, you should be concerned. Drought stress, especially cumulative drought stress, is pretty hard on almost all trees, and one way some kinds of trees deal with it is to “go to sleep” a little early. Evergreens as a rule don’t have the luxury of laying off its employees (shedding needles or leaves) and drought stress is especially hard on them.
Very rarely can an evergreen completely defoliate, and regenerate new growth to survive.
I have seen a few do it, but it is quite rare. If, for example, your Manzanita turns brown all over, it is most likely toast! The next way to look at your tree is from beneath. If when looking up from under, and you see more green (foilage) than blue (sky) you are doing great! If you see more blue than green, it will be cause for concern, and you should think about giving an arborist a phone call… Keeping a log or journal about what your tree does and when it does it is a great idea. Dated photographs help treemendously as well (pun intended). Just the “cast” or hue of the canopy can give you an idea of the trees mood. An ashen or dull look to the overall color can be an indication that something is amiss, and further examination is needed. This can be hard to spot, but if you practice enough, you will eventually get it! I am seeing a lot of parched trees around town, some to the point of no return, and this shows that one wet winter doesn’t pull trees out of a drought spiral… With city water rates being what they are in summer (shocking) The money you spend on mulch will be very well spent.
Consider going in with a neighbor or two and hiring a water truck to irrigate your trees, It is kind of a new idea of mine, but I don’t see why it wouldn’t work. If you haven’t watered your trees this year, now is a good time to give ‘em a good soak.