http://www.nytimes.com/2016/10/11/science/trees-new-york-city.html 2016-10-10 22:33:14 The Trees of New York City Why do I see only deciduous trees, not evergreens, planted along New York City streets? === Q. Why do I see only deciduous trees, not evergreens, planted along New York City streets? A. The most recent census found almost 8,000 of them, but the number is growing. At least eight new varieties, a total of 5,600 trees, have been planted since 2009. The choice of a tree for each site is made only after a detailed assessment of the conditions, Mr. Strauss said. More evergreens and deciduous conifers are planted these days because field observations suggest more places around the city in which they are likely to grow well. As it turns out, the dawn redwood and the bald cypress, both deciduous conifers, tolerate drought and compacted soil — a virtue in New York. The Chinese juniper and the eastern red cedar, two evergreen conifers, are highly tolerant of aerosols and high wind, so they are planted along shorelines. The golden hinoki cypress is slightly more sensitive, better for areas with lower foot traffic and less pollution. As more new species are planted, they become more available from nurseries, Mr. Strauss said.