Silk Oak and High Voltage

NW corner of Douglass and 24th Street.
Client: Noe Valley Association.
Climbers: me, Marcello, and Sean.
Ground Crew: Kent, Mikey, and Serge.
Common name: Silk-oak (not a true oak).
Botanical name: Gravillea robusta.
Family: proteaceae (yes, the same family as those plants with the crazy, alien like flowers).

Above: a picture of the leaf and flower

Below: a picture of three of the five trees before pruning.

Silk Oaks, Gravellia robusta do not belong under high voltage power lines. They grow to be 60-100 feet (usually only 60 feet). They grow really really fast. There are several examples of topped Gravellia robusta throughout San Fransicso. There is one at 18th and Valencia also under high voltage power lines.

Topping street trees, meanwhile, is illegal. PG&E does it all the time to trees below power lines. I guess they get away with it out of necessity. Many times there are ways of removing branches that encroach on power lines without topping. But this requires a more delicate touch. I have been called upon many times to clean up trees messed up by PG&E.

The best thing to do is plant small trees under power lines.

It’s not just PG&E that tops trees. Business owners do it so that people can have a clearer view of their signage. Apartment owners do it becasuse it is cheaper than paying an arborist. Homeowners do it because they don’t know any better. If you see tree being topped you should report it immediately. Speaking up is the only way to stop our city trees from being destroyed.

How do you identify a topped tree? How do you report the crime? click on the following link:

This was a long hard day of tree trimming. Serge, a powerhouse on the ground, got sick. He went home after a few hours. That left it up to 5 of us to finish the job. It was also incredibly windy after lunch.

A branch knocked over the pedestrian barrier which shattered a 10″x11″ pane of glass in a restaurant window. During lunch I found a company to fix it. It took him 20 minutes to fix it then he tried to charge me $220. Highway robbery.

These trees were in rough shape. The prior topping led to giant vertical suckers, rotten stumps unable to compartmentalize, and elongated lateral growth. There were several signs of branch failure. The goal was to reduce the height, remove rotting stubs and failed systems, and remove long laterals overhanging the street. Of course, we wanted to make them pretty to look at too.

These trees are in a high risk zone. They overhang a bus stop and several busy shops. If a limb were to fall, the stakes would be high.

I think we really pulled it off. Although they don’t look anything like they would in nature, they now have an urban elegance. Most importantly, they are much safer for the public.