Date: Fri, 17 Apr 2009 10:01:44 -0400
From: Al Cooke
Subject: Bradford Pear Dilemma
Re: the Bradford Pear Dilemma
Your Chatlist post about the Bradfords caught my attention. I don’t have The Answer, but can offer a direction of inquiry. At 12 foot spacing, the trees probably are too close together to ever reach full potential, but that is not likely to kill them. The presence of shoots coming out of the trunks (water sprouts) is evidence of a tree in decline but not typically a cause of the problem. It may be worth noting that all Bradfords are grafted on Callery pear rootstock and anything below the graft is technically not a Bradford.
For the most part Bradfords do not have significant problems from insects and disease. Their major defect is weak structure subject to breaking. From your description, I suspect there is little salvation for these trees, but a couple of thoughts come to mind. Their decline may have begun during (or even before) the drought of 2007. Mature trees usually take several years to decline. It’s common for trees to die several years after construction damage to roots.
It may be worth doing a little excavation around the base of the trunk of these trees. I sometimes find that trees were planted without removing materials (wire baskets, synthetic burlap) that don’t rot and which subsequently girdle the trees. And sometimes I find them too deep, either from deep planting or from settling after planting. You should find, at or slightly above the soil grade, a buttress flare at the base of the trunk from which roots begin. Tree trunks should not look like telephone poles emerging from the soil; there should be a buttress flare and gradual taper.
As I said, I don’t have the answer. After you look a little further, if you want to give me a call, please do. Sometimes it takes a little detective work.
alcooke
Al Cooke
Extension Agent, Horticulture
Chatham County Center
N.C. Cooperative Extension
PO Box 279, Pittsboro, NC 27312
919.542-8202; Fax 919.542.8246
http://www.ces.ncsu.edu/chatham/staff/acooke/home.html