Fungus or phytotoxicity on Kaede


Hi all,

I have been having problems with an arce buergerianum. During the past few months I noticed that its leafs are curling and turning brown. First I though that it was due to the heat at which I started to increase the watering intervals, but the issue continued. Now I think this might be due to a fungus. I been treating all my trees with insecticidal soap due to spider mites (seems they are freaking inmune to everything). The thing is that I did not know until very recently that it might be phytotoxic to trident maples and I do not know what could be causing the issue. Attached is a picture of the leafs. Any recommendation?


(Frank Corrigan) #2

The picture is a start but it simply raises more questions. it would be helpful if you detail the following information.
What media the tree is planted in?
Where you are located climate wise, this is important.
What has the tree been through recently, repotting,pruning, wiring etc.
The statement that you have used insecticidal soap is very general. Which types have you used and what is the frequency of application? Phyto toxicity is dependant on ingredients!
What type of fertiliser do you use and when was it last applied.
Not trying to be difficult it is just factual that a reasoned response depends on the above information being provided.


I got this seedling last november. Because it was too late for transplanting I just putted it a mix of coconut fiber, lavarock and pumice (1-1-1) without messing with its roots. I was thinking on moving it to akadama and kiryu next spring. Its been living under the Texan sun in Dallas. Although it gets very hot in the summer, in the spring and fall gets very humid. No pruning or wiring at all. The insecticidal soap is the safer brand with potassium salts as active ingredients. I have used it every other week during the summer when the temperature allows.

The fertilizer I been using is Espoma plant tone and fish emulsion during the spring. I stopped fertilizing in the summer.
Because of the summer heat, I installed a misting system that runned in the hottest day of the summer (a possible contributor of the problem). I have been fighting againts some spider mites on an elm I have, thats why I applied the insecticidal soap on all my trees. Hope this helps find the real culprit (is possibly me).


(Frank Corrigan) #4

Based on your response i would suspect root issues due to the manner in which it was transplanted and too much moisture trapped in the roots with the watering methods.
This is based on not teasing out some of the roots in the old media to help the plant expand to the new media and the color of the leaves indicating excess moisture or lack of certain nutrients. The uptake of nutrients could also be affected by very alkaline water!
The first step i would take is to examine the rootball carefully to ensure healthy roots and then go from there based on the results. Check a section to find out what is happening.


I have to say that root rot was one of my guess. I check the root ball and everything looks fine. Not a single rotted root. White roots every where.

Alkaline water… I have to check it. I believe I have some Litmus paper around. I will check and update on that.

Thank you


I just checked the water pH and according to the Litmus paper it is slightly above 7. What do you think? Would that be the problem? What do you recommend?
Also, I though that organic fertilizer were acidic, doesn’t that help?

(Frank Corrigan) #7

PH 7 is not a problem. What does the whole plant look like? The picture just shows a few leaves. Do you have any pictures showing the tree overall, the stems and branches. It is very hard to interpret part of the picture. Perhaps it would be best to show it to noe of the local experts that could view the tree in person.

(Ανδρέας Γάβρης) #8

Excellent approach to the subject. :grinning:


Maybe I haven’t mention this before, but the tree is a seedling. Is very difficult to capture details in a picture of something so thin unless I zoom to a specific zone. Is there is something I should look for?