- Written by Kevin Lee Kevin Lee
- Published: 06 July 2019 06 July 2019
It would break your tree loving heart: a beautiful nearly 30 year old white flowering Siberian crab apple, with 60% die back in the last month. Why so fast?
The owner knew something was wrong, but what? And who can help? She had two different tree services out in the last month. Both of them misdiagnosed the problem, the problem was a very serious one called fire blight, a bacterial disease of certain plants related to apple trees.
There are not a lot of tree diseases in Calgary and this one is entry level, one that every working arborist should know. One of her diagnoses was that the tree has scale, the same oyster shell scale that most of our cotoneaster hedges have. The tree has no scale, it does have tiny white spots on the young bark called lenticils; these function as pores. The other diagnosis was a shrug and the selling to her of a fertilizer application.
Fertilizers contain no food, no energy, really what they do is trick a tree into spending stored energy, exhibited as new shoots. These unnaturally fast growing shoots are doubly susceptible to fire blight. Growing at an accelerated rate the trees' immunity, or ability to defend themselves from the bacteria is lower than naturally growing shoots.
A tree that is in trouble, is sick, dying can not be propped up with fertilizer, in this case it was the death knell. The disease now given an extreme advantage, took it. The decline in less than a month is dramatic.
One of these Arborists either is or works for a service that proudly claims International Society of Arboriculture certification. They missed the boat, took her money, sent the tree to the gallows, and went home after another day at the office.
The internet is a mind boggling tool, be careful, very careful.
If you're wondering why your tree is dying, please contact me for a consultation here.