The Homestead Hobbyist

Originally posted on Agritate, which is no longer active.

It isn’t necessarily a logical assumption that more heat would help plants grow—it certainly depends on the plant. Researchers in New York City looked at red oaks and how their growth was impacted by temperature in the city, finding that because of the general increase in temperature within a city, the trees grew a ton more than those planted outside the city. The biggest correlation between temperature and tree growth was the increase in nighttime temperatures—the temperature doesn’t drop as much in the city as it does elsewhere, which allows trees to be more biochemically active at night to prepare for daytime photosynthesis and growth.

It’s an interesting point, but something we gardeners have always kind of known—straight-up tropical plants are often grown here in Washington DC, whereas just miles outside of town the attempt would be futile. The cherry blossom trees planted near light- and heat-reflective walls of buildings bloom the earliest each spring. Kale, however, freaks out and bolts earlier than it would were it not in a “heat island.” So, pros and cons—and the effect climate change will have on urban forestry will necessitate a change in the trees used to canopy a city.