I bragged of this impressive newsgroup to my landlord and he asked if I
could find out why sections of our Maple trees seem to "burn out." It's not
happening to all our Maples, but some. And it happens every year. This year
we're having a particular spotty problem (curious about it also) but we have
the early-burnout problem every year. What causes it?

oops, meant to include this link:

http://www.junkshop.com/maple_burnout.jpg


On 14-Aug-2004, "FlatTop" wrote:

I bragged of this impressive newsgroup to my landlord and he asked if I
could find out why sections of our Maple trees seem to "burn out." It's
not
happening to all our Maples, but some. And it happens every year. This
year
we're having a particular spotty problem (curious about it also) but we
have
the early-burnout problem every year. What causes it?

he asked if I could find out why sections of our Maple trees seem to "burn
out."
This year we're having a particular spotty problem

By "burn-out" I assume you mean leaf scorch, that is the edges of the leaves
turn brown & the leaves get raher dry. You don't mention where you live or
which species of maples. In general, most maples are from cool forest areas.
Some of them are not suited to growing alone in the sun in a climate with hot
dry summers. Their thin leaves get scorched. Usually, it is a cosmetic problem
and the trees themselves survive, as long as the roots get enough water. If
these are adult trees, there is nothing you can do about it, unless you want to
stand there every hot sunny day and spray the entire tree with water. The other
thing you can do is make a note of which trees are affected and don't plant
that species when you own your own home.
The leaf spotting is a fungus disease caused by our unusually rainy summer. It
is also basically a cosmetic problem. It is too late this year to do anything,
but in the fall, be sure you clean up all the infected leaves and get rid of
them. In the spring, any time they are predicting a lot of rain, have the most
sensitive trees sprayed with a fungicide by a certified arborist.
Iris,
Central NY, Zone 5a, Sunset Zone 40
"If we see light at the end of the tunnel, It's the light of the oncoming
train."
Robert Lowell (1917-1977)

Thank you so much! I live in Michigan. Your explanations are most
enlightening.

It really depends on where you live in Michigan. If it's the southern part,
summers can get pretty warm and dry.

However, from the pictures of leaves I'd suspect a blight of some sort --
fungal or viral, I can't say. This happens with moisture stress, as Iris
mentioned.

Your local agriculture extension agent or bureau of forestry (Michigan State
University should be able to help) could give you more information. If it's a
problem for you, it may be a problem for others.

C Manville

allrighty. it's southern michigan, and we've had some weird weather this
summer -- may was the third wettest on record -- so that could help explain
the blight. alternately, the general leaf-burnout thing is yearly, and, from
what you experts say, might just be a factor of the particular maple(s) in
the particular climate. we have maples in the yard (probably of a different
kind) that are beautiful and green and don't burn out -- but do have the
blight.

i'm amazed at what a resource this newsgroup is (i just happened upon it
when i needed a plant identified last week) and i'm tempted to go house to
house charging people $10 for a 24-hour response to all their plant
questions; and i'll simply come here and get them answered quickly and
correctly -- and make a million!

which is a long way of saying thanks for your answer.

Iris asked about the species -- I don't think the species is native to southern
Michigan.

The species native to southern Michigan are silver maple, red maple, and sugar
maple, with the occasional black maple. The leaf shape in your photo seems more
like a young Norway maple. Iris, do correct me if I'm wrong about that.

Do consult an arborist, or the forestry extension.

"FlatTop" wrote in message ...
I bragged of this impressive newsgroup to my landlord and he asked if I
could find out why sections of our Maple trees seem to "burn out." It's not
happening to all our Maples, but some. And it happens every year. This year
we're having a particular spotty problem (curious about it also) but we have
the early-burnout problem every year. What causes it?

Looks like it might be maple anthracnose based on the photos on the
following page and your photos:

http://www.cfl.scf.rncan.gc.ca/colle...ie_e.asp?id=30

Google.com has several webpages on maple anthracnose, which occurs
during cool wet weather. If the weather is very dry and there are no
fruiting structures on the leaves, then it is probably drought injury
as already mentioned.

very interesting. perhaps i will photograph and post some pictures of the
various maple leaves -- from the green healthy trees and the burned out
ones. it might indeed be a species issue. thanks.

very interesting. we have indeed been having cooler, wetter weather than
normal. i think. i think maybe you've hit something. thanks.

The leaf shape in your photo seems more like a young Norway maple. Iris, do
correct me if I'm wrong about that.

I didn't see the picture. I have rarely seen Norway maple with leaf scorch in
the Northeast, so I doubt they would get it in Michigan year after year. The
most likely to get it would be Japanese maple or some other exotic species. The
tenant or his landlord should consult a field guide.
Iris,
Central NY, Zone 5a, Sunset Zone 40
"If we see light at the end of the tunnel, It's the light of the oncoming
train."
Robert Lowell (1917-1977)