Many of you may remember that line from the character played by Jeff Goldblum in the original Jurassic Park movie. His argument was that man’s best laid plans can be defeated by an organism’s will to survive and procreate in the natural world. Thankfully you won’t have to escape the jaws of a tyrannosaurus rex on the way home from work today, but you may notice a less terrifying example of the same principle. The reproducing and spreading species in this case is the ornamental tree called the callery pear, which may right now be in its full flowering glory in your front yard.
Native to China, callery pear has been in cultivation for many years. Its cultivars are known by a variety of names such as Bradford, Aristocrat and Chanticleer. In recent decades they have been among the most popular ornamental trees due to their early and showy white flowers and their red and purple fall foliage. Their growth form, often with spherical crowns, gives a manicured look and has led to the slang name of “lollipop” trees.
Some cultivars are not capable of self-pollination and don’t produce viable seeds, except when they receive pollen from other callery pears with a different genetic make-up. Others were supposedly incapable of spreading by seed but are grafted onto a seed-producing rootstock. Sprouts from the base of the tree, if not removed, can produce flowers that will cross with the flowers in the crown to produce viable seeds. Because the pears are susceptible to crown damage from high winds, they can also sprout from the base after storm damage.
Regardless of the method, callery pears have definitely found ways to escape from our front yards. They can be seen right now like white clouds along many roadways and in waste ground near where the ornamental trees were planted. The spreading trees often produce thorns that make them more difficult to remove. If you have callery pears spreading on your property, please cut them down and treat the stumps with herbicide to keep them from re-sprouting. If you are selecting trees for new plantings, consider native alternatives or non-natives that are not known to spread.