“We ordered the special of two compatible pear trees and only
received one, the dwarf Flemish Beauty, last year. We planted it and it
seemed to flourish, the winter was a hard one however. I did use a tube on
the trunk for insulation. The snow drifting was very bad and the lower two
branches were broken off at the trunk after the thaw. However, it leafed
out and then the leaves all drooped and turned black and I noticed a
softening on the trunk just below the leafing branches. I found some
surviving leafed stubs under the insulating tube, but they are only 1 -2
feet off the ground. Is the whole tree a loss? I planted the new dwarf
Clapp’s Favorite that we ordered this year before the other one started
going bad and it seems to be doing fine. What should I do? Thanks, Sally”
Thank you for the email regarding your pear trees. When observing black
leaves on pear trees, it is important to rule our fire blight. The symptoms
do not appear to be those of fire blight, so we will rule it out first. That
is good. Fire blight is a bacterial disease which is difficult to manage.
A common problem observed in trees in Wisconsin each spring is blackening of
leaves of pear, cottonwood, and many other trees. This can be due to slight
frost damage or by wind damage. The frost damage may have occurred on a
night in which temperatures at location of most thermometers registered
temperatures above freezing; the frost may have been localized to small
Young leaves in the spring are often very tender and subject to damage from
the winds which develop during the spring when temperatures begin to warm.
Temperatures can rise to very pleasant to rather warm mid-day temperatures
in spring and then be followed by cool nights or gusty thunderstorms. When
combined with spring winds, the tender leaves can have rapid desiccation
because they have not developed enough yet to have the proper protection and
sturdiness that a summer leaf would have. The leaf margin is the most likely
injured part of the leaf. This desiccation can occur even if the soil has
adequate moisture because the wind can draw water from the leaves faster
than the tree can move it from the soil into the leaves. Newly transplanted
trees, with limited root systems, and those which have just begun rapid
growth after a couple of years establishment following transplanting may be
the most likely to show the symptoms. However, under the right conditions
this spring wind desiccation injury can occur in larger trees as well.
The soft trunk is normal, as long as it is not soft like a sponge or cotton.
Thin branches and rather new trunks have not developed enough xylem (the
‘wood’ in a tree, formed of cells that conduct water) to give it the
hardness that would be found in an older tree.
As long as the tree appears to be otherwise healthy, there should be little
to worry about or your new tree. Pamper it a little by making sure that it
has water and fertilizer. Wisconsin’s climate can provide some harsh
environmental conditions which cause cosmetic defects in many of our
landscape and garden plants. With the unique weather we have been having,
this has been a common problem for those with fruit trees.
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