Street Tree Numbers are Down - and there's a Reason


The Department of Public Works (DPW) Bureau of Urban Forestry recently announced that the number of street trees removed by the City in 2017 exceeded the number of trees planted - meaning the total number of street trees in San Francisco went down last year. That’s not a big surprise - with the passage of Prop E in 2016 (now called “Street Tree SF”), the City took back responsibility for all street trees in the city, and with a backlog of aging, sick or dead trees, most experts expected there to be an upward blip in removals.

However, there’s another structural reason that tree numbers may continue to decline, which I noticed when DPW tagged a number of trees in my neighborhood of Cole Valley for removal (one of the notices is in the photo to the left). If you look carefully at the notice in the photo, you’ll see that a total of 21 trees were tagged for removal, but (look at the bottom of the flier) only 12 permitted to be replaced. Why? In some cases, the existing trees were too close to underground utilities; in other cases too close to streetlamp poles. In yet other cases the trees were too close to other existing trees. DPW maintains a set of standards for planting street trees, and in some cases these rules have tightened over the years, so a tree basin that was plantable years ago may no longer work today.

What this means is that there is a structural factor that will result in fewer street trees, year after year. DPW’s rules for the placement of street trees are there for a good reason, and I’m not suggesting that they be changed.* However, we need to realize that as we lose street trees in the ordinary course of urban life - from age, or disease, or getting hit by a delivery truck, many of them won’t be replaceable.

What’s the solution? We need to accelerate plantings in places where no trees existed before. And now that the City is in charge of our street trees, that means getting more funding. We all need to push our supervisors for more funding for street tree planting - because if we don’t, you’ll start to see fewer and fewer trees in the neighborhoods.


* OK, I do have one quibble. The City disallows trees within a few feet of a streetlamp pole - because you don’t want a tree blocking light to the street. But there are plenty of small trees that would work in those spots, and never grow large enough to be a problem. Especially now that DPW controls things (including the species of trees that get planted), I think that’s a rule that could be relaxed.