Callery Pears Becoming Extremely Invasive!
Although ornamental flowering pears are beautiful in the spring, they have several severe problems. Below is a portion of an article written by Sandy Mason, Extension Educator in horticulture based in Champaign, IL. Since this article was published in 2005, ornamental pear problems have escalated out of control with even many more municipalities banning their use.
Bradford's have a nasty habit of crashing just as they reach their glory at 15 to 20 years old. Its branching habit is to blame. It develops weakly attached branches with narrow crotch angles. Plus there are usually 6-8 branches coming from the same point on the trunk. They look like upside down umbrellas. Often large limbs are lost in wind and ice storms, but can also fall on a calm day. Typically limbs rip down the trunk and give the tree a very unsymmetrical look. The trees are doomed to a pruning cut at ground level.
'Bradford' pear is a cultivar of Callery pear. A number of new Callery pear cultivars were introduced with different branching patterns, in the hope that they would have less chance of breaking apart. Bill Vander Weit, City Forester for the City of Champaign, states, "We have planted several of the improved cultivars of Callery pear and have found them to have the same tendency to branch failure that we find in 'Bradford' pear. In particular we have experienced branch breakage with 'Chanticleer' and 'Redspire' pear. The 'Aristocrat' pear seems to hold some promise because of a wider crotch angle, but I am still wary on how they will hold up over the long run. Because of this we have planted 'Aristocrat' pear in small numbers, and have used them only in harsh soil environments where other trees have difficulty surviving."
Another problem with the "improved" pear cultivars, is that they cross pollinate with 'Bradford' pear. 'Bradford' pear was originally introduced as a fruitless tree. Suddenly 'Bradford' and other pears began to produce large quantities of marble size fruit. This fruit was carried, probably by birds, so that now hybrid Callery pears are showing up along roadsides and in forested areas where they will out compete and displace native species.
Because of these problems, the City of Champaign will no longer permit the planting of Callery pears on the city right-of-way. Vander Weit states, "The main reason we are banning pears is due to their tendency to break up in storms. The past couple of windstorms we experienced really drove home this point. Despite the fact that pear makes up only 5% of Champaign's total tree population, nearly 50% of all damaged trees we responded to were pears. Many of these were private trees that split apart and fell, with branches covering a lane of traffic. Also we are concerned with the escape of a non-native tree into the wild, and do not want to contribute to an already long list of exotic invasives that choke out native flora."
Please take Sandy's advice and don't plant ornamental pear trees. For help finding an alternative, go to the University of Illinois Extension website "Selecting Trees for Your Home" at http://urbanext.illinois.edu/treeselector.
Watch a video on the invasive Callery Pear on the Midwest Invasive Plant Network website at http://www.mipn.org/.
University of Illinois Extension · U.S. Department of Agriculture · Local Extension Councils Cooperating
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