Subtropics move into New England

A Crepe myrtle. They’re moving into southern New England.

Japanese knotweed

From Robert Whitcomb’s “Digital Diary,’’ in GoLocal24.com

Because of Nantucket’s relative proximity to the Gulf Stream, people used to joke that you’d soon be able to grow palmettos there. Well, that might happen in the next couple of decades as man-made global warming accelerates.

I thought of that while reading an article in the July 27 New York Times entitled “Imagine Central Park as a Rainforest,’’ which described the proliferation of plants moving from the south into New York City, which, like Providence, the National Climate Assessment now places in the “humid subtropical zone,’’ a shift from its previous placement in the “humid continental zone.’’  The growing conditions  are now similar to those in Maryland.

Such trees as crepe myrtles and magnolias have become common in New York City and southern New England, as are such invasive and warmth-loving plants as Japanese knotweed. I’ve noticed a host of new weeds cropping up in our little yard the past few years.  Plants, including flowering trees, are blooming earlier and lawns tend to stay greener later in the fall. Unfortunately with the southern plants come southern insect pests that we must learn how to suppress without poisoning a lot of “good’’ plants and animals in the process. (By the way, I have found that cleaning vinegar (6 percent acidity) is a safe herbicide. Or you could stick with Roundup and give yourself cancer.)

None of this is to say that the “polar vortex’’ won’t briefly but memorably slam us in the winter from time to time, so it’s a little early to think we can put out palms year round. But the direction is clear.

So southern New England gardeners will have an increasingly exotic time of it.

Hit this link for The Times’s story.