Japanese Larch...Sick or Fall needle drop?

[scottfro]

Hey Folks,

Pretty new to this forum and looking for some advice. I have two Japanese larches that I purchased this year. They were doing great all season but as of about a week or so ago, one of them had all it's interior needles turn brown and drop. There is still green growth on the exterior of the plant. The other larch has been treated the same in terms of watering, etc and is still quite green. Any thoughts on what might be going on? See attached pics.

One pic shows the inside of the tree, and the other shows the growing tips which seem healthy still.

Thanks!

 

[fourteener]

It looks healthy. Usually the needles turn yellow around the whole tree before they drop their needles. Is the soil dry? Have you changed the light conditions? Sometimes trees drop their foliage in response to dryness or new conditions.

 

[scottfro]

Nothing too seriously has changed. No repotting, basically the same watering schedule, light, etc. The colour change to yellow/brown then to needle drop was so quick that it seemed to imply something was wrong.

 

[Nybonsai12]

Look similar to what happened to one of my American larch. I don't know what it is but it is similar in that needles went from green to brown. I believed it was some sort of fungus. I sprayed mine with copper and that seemed to put a stop to it.

 

[twisted trees]

Look similar to what happened to one of my American larch. I don't know what it is but it is similar in that needles went from green to brown. I believed it was some sort of fungus. I sprayed mine with copper and that seemed to put a stop to it.

I'm in the Finger Lakes region of New York and have a great amount of larch. All of mine in nursery pots are yellow now. Of course fall is kicking up and we are at about 20% of our fall color. Usually when needles drop and green is left at the end it is a sign of either heat stress or normal fall changes where the newest shoots can sometimes retail green foliage through the winter. If the buds are full and the branches are supple I would not worry. I use bloom fertilizer this time of year to strengthen the roots and buds.