Transcript:

Trees That Don't Grow in BrooklynMaples, oaks, honey locusts, some of the shade trees most typically planted along city streets. But what kinds of trees wouldn't you want to have in an urban environment? I'm Jim Metzner and this is the Pulse of the Planet.Heavers: The trees you wouldn't want in the city are the trees that drop their leaves very frequently. Nathan Heavers is an Assistant Professor in Landscape Architecture at Virginia Tech.Heavers: Some trees shed leaves not just in the fall but at periodically, in small droughts often, during the course of the summer. Other trees have very large nuts or fruits that drop that can be messy. For instance, the black walnut is a beautiful tree, but it's rarely found in cities because of the size of the nuts and the frequency that people would be walking under them. Another one that Americans don't tend to like is the mulberry tree, which drops its fruit and becomes messy on the streets. There are also issues with things like the other animals in cities, like the rats, can feed off of different fruits and nuts that you might find in cities. That also is a concern for a lot of people.Trees that you might not want to plant because of what they do underground are actually some of the trees that we plant. It's a bit of a trade-off. The red maple, for instance, tends to lift and heave sidewalks break apart the structure of the sidewalk but it also is a great shade tree and can survive some of the droughts that we have in the city. Evergreens tend to hang on to their leaves for a longer period of time than other trees.We don't see evergreens in cities because they have these fine needles that often get covered in the dust and the grime of the city. They grow well in very harsh environments, often cleaner environments where there is not so much air pollution as there tends to be in the city.I'm Jim Metzner and this is the Pulse of the Planet.