Zelkova serrata forests

[aneesto]

Please please please help - my zelkovas got affected by this starting in july/august. thought it was high heat and humidity due to zone 7a/b location and therefore fungus. But october has passed and the weather has cooled off and the browning has progressed. When browning started first i used Bonide pesticide thinking its fungus and i cut off the browning parts. that was 6 weeks ago. and since then this is how much (A LOT) browning continued to occur. This gotta be fungus and i just need to apply the bonide product every say 10 days several times? And do i remove all the leaves? Although these guys were near a chinese elm corkbark that got affected by gnats or something and lost some leaves.

They are outside in full sun on a windy balcony in a high rise building.

 

[JudyB]

Could be dry soil on a windy low humidity day, could be too wet soil, could be the start of the fall cycle of dormancy starting... Where are you located, that will help your answers be more accurate. If you're at the end of your growing cycle, I would not get too nuts about this as it's about dormant season. I would be proactive with daconil next spring if indeed this is a fungal issue.

 

[aneesto]

Could be dry soil on a windy low humidity day, could be too wet soil, could be the start of the fall cycle of dormancy starting... Where are you located, that will help your answers be more accurate. If you're at the end of your growing cycle, I would not get too nuts about this as it's about dormant season. I would be proactive with daconil next spring if indeed this is a fungal issue.

its climatic zone 7a/b so arlington virginia on the US east coast. but thing is that the plans have spent the last month in an east facing garden with only morning sun and surrounded by a lot of trees, also feel like there was much less wind there so i was surprised to see so much browning still. Im just worried about the trees not dying over the winter due to the fungus. There is a chance that im overwatering them - its my first time with zelkova serrrata so i dont quite get it. I got ficus down, i think, but this is a new species to me. Dormancy - i thought that would mean nice orange colours of leaves not leaves browning from the tips to the center.

thank you

 

[BrightsideB]

Usually if leaves start getting dry and brown from the opposite side of the stem. It is usually a transpiration response. Leaf losing h20. Also it happens as the tree draws resources from the leaf in fall but generally the leaf turns the fall color but not always. Fungus is usually presented in a blotchy type of configuration on stems or leaves with different colorations.

The tree is most likely stressed. But I think they are fine and won’t die. They are getting ready for dormancy at this point. Also the way the leaf presents its fall colors can also be attributed to its personal dna. But also its care.

 

[Kievnstavick]

I would agree that this seems to be a hydration issue rather then a disease. The buds look plump and healthy for next year.

As we are approaching winter, I would not stress over the leaves. My zelkova saplings have similar looking brown parts of the leaf, although mine is a couple of leaves out of dozens.

Make sure to properly water your trees next year and fertalize correctly. Too much fertilizer can cause salt burn. Also remember that if the tree is low on water, the wind can effectively "burn" the leaves by removing the water from the leaves.

Unless you have a serious infection of gnats in a confined space, gnats wouldnt cause lasting damage to your plant. Gnat consume fungus. The fungus grows on decaying organic manner. The gnats would need to be desperate for food to consume the roots. They are more of a nuisance and gross then harmful.

 

[rockm]

It's autumn here, which is contributing to your issue (which is probably wind/hydration related). Also you have Chinese elm not Zelkova. Chinese elm is sold as zelkova to get around importation restrictions.