Saturday, March 17, 2012

Callery Pears Spreading

Last year we posted a blog story warning about the invasion of Callery pear trees, escaped Bradford pears which supposedly are sterile but still manage to engage in hanky-panky.  The resultant wild Callery pears can grow anywhere and frequently revert to their thorned variety.

Callery Pear- Click to Enlarge
Barb now not only moans as we pass Walmart and shopping centers, thick with the domestic trees but points out the proliferating trees found in fields and disturbed roadsides within sight of our urban house.  I am afraid that it is just the beginning of a wave of white, capable of displacing some of our native species.

Susan Farrington, a Missouri Department of Conservation Natural History Biologist - Ozark Region, sent out the reminder and some suggestions for action which are below.

"Callery pears are in full bloom in southern and mid MO right now (and perhaps further north even). If you aren’t already aware of the threat these trees present, I would be happy to forward you information about their very invasive tendencies. They are creating a white haze all around West Plains right now, and are invading our conservation areas.

To help you readily identify them, download this PDF file  I put together of photos of callery pear, Mahaleb  cherry (an exotic look-alike to the pear, also invasive), and two good natives (serviceberry and native plum) they might be confused with.  “(Some of these photos are my own, but most were taken from the web and in my haste to distribute this in a timely manner, I did not list all the photo credits.)”  Hopefully this will allow you to id them even from a distance as you drive through our conservation areas.

If we can catch the invasion of these trees early on, we can save a lot of time and trouble in the future, so if you see just a few scattered on a conservation area, please flag them and note their location. As long as we can return and kill them by mid summer or so, we’ll stop them from forming ripe fruit. They are MUCH harder to find once all the other trees leaf out, so flagging them now is important.

Do not cut them down unless you have herbicide at hand: they will just re-sprout with a vengeance."