Why are older pines and cypresses on the Peninsula failing?

Because they are all the same age. The Monterey pines and cypresses planted through Daly City, Colma, Montara, and the coastside tracts in the 1950s and 60s are now 60 to 70 years old - near the end of their natural span. Add the local conditions and the pattern is predictable: Pitch canker has weakened much of the pine population Decades of one-directional ocean wind have built permanent lean and uneven crowns Salt-laden fog keeps foliage heavy and stressed When these trees fail, they fail onto houses spaced a few feet apart. An assessment tells you which of yours have years left and which should come down on your schedule instead of the storm's.

Because they are all the same age. The Monterey pines and cypresses planted through Daly City, Colma, Montara, and the coastside tracts in the 1950s and 60s are now 60 to 70 years old – near the end of their natural span. Add the local conditions and the pattern is predictable:

Pitch canker has weakened much of the pine population
Decades of one-directional ocean wind have built permanent lean and uneven crowns
Salt-laden fog keeps foliage heavy and stressed

When these trees fail, they fail onto houses spaced a few feet apart. An assessment tells you which of yours have years left and which should come down on your schedule instead of the storm’s.