Patch Blog: Why Did the Trees Fall?

There has been talk suggesting that the widespread loss of massive trees was due in part to us: wrong tree, wrong place, wrong care. This kind of bothered me because I wanted to hear it from experts, from arborists.

So I did a Google search and found an excellent article by LA Times reporter and blogger Emily Green called, How to prevent your trees from looking like this. Only thing is, the article was written a year and a half ago.

Although the loss of trees during this unusually violent Santa Ana windstorm may have been inevitable, we know that many of our trees were at high risk because of how we select, plant, and care for them. Trees fail because we baby them. We over water them so they don't have to develop deep, broad, supporting roots to get water. We water frequently and for short periods so the roots grow near the surface, where the water is. Furthermore, when the winds came, trees standing in soggy soil may have been an easy push-over.

We stake trees when they are young under the misconception that this will result in stronger, straighter trees. Not so! They cannot sway and move, and this is what is needed for the development of a strong root system.

We prune trees badly so the growth above ground is not in balance with the roots below. After severely pruning a tree, there is not enough energy generated through photosynthesis to feed the root system. The tree may respond with a flush of growth above, even though the roots are diminished. It takes time for balance between the top and bottom to be restored, but we just keep hacking away at the branches, year after year.

And of course, we plant fast growing trees because we can not wait for a steady oak to grow. Though this may provide quick gratification, especially when water and fertilizer further accelerate growth, the results are brittle, unstable, shallow-rooted trees that stand hazardously close to our homes.

Which brings me to in South Pasadena. As mentioned by Drew Ready of the Council for Watershed Health, the park was hard hit. Pines trees fell, acacias toppled, sycamores snapped, and three wonderful, massive coast live oaks were uprooted.

I jog daily at Garfield Park, and I can say with certainty the park is maintained to protect the grass, not the trees. The grass extends right under these beautiful oaks and is watered year around. The soil is usually soggy. The trees look okay ... except when they don't. Over the years the oaks have been disappearing. Some fall, some die standing. Looking at the roots of the newly fallen, one is struck by how small they seem.

Yes, they were ripped apart in the storm, but the question remains: If we did not have grass growing beneath them, and if we did not water them constantly, would more have survived? No one knows the answer for sure, but it seems logical.

It is time to turn off the water in Garfield Park. Under the supervision of expert arborists, the City should begin to wean these heritage trees from the artificial and damaging conditions  that are killing them. Maybe it would be a good idea to spread wood chips made from the glorious specimens that fell, around the survivors to increase the chances that they will stand for another hundred years.

Links:

LA Times, Emily Green, How to prevent your trees from looking like this.

LA Times, Emily Green, Why did santa ana winds fell so many trees?

LA Times, Emily Green, Now that the winds have departed.

Joe Piasecki, Pasadena Sun, Fallen trees: the root of the problem in Pasadena (quote by Drew Ready, Council for Watershed Health)

KPCC, Santa Ana winds blow through Southland toppling trees, power lines