Morning, This Spring I have found half of my JMs both in-ground as well as in pots are carrying these type of spots. They are from 1/16" to1/8" in diameter. Is this fungus due to the cool Spring season in the east coast or some kind of disease?. I am afraid it may be too late to spray now but I am seeking for any advice to prevent it to return next Spring. The trees look healthy but not as beautiful as they should be due to these spots. I was at HomeDepot last week and I also saw their red lace-leaf had the same spots as mine. Any suggestion is appreciated, steven.
I've always wondered about this and would be interested in all opinions.I've always put it down to a minor water uptake issue,perhaps a hot/windy spell catching the plants out after a dry period.As you say it doesn't seem to bother the plants or spread so I don't think it's a fungus.Personally I don't believe the theory of water droplets acting as lenses and burning the leaves as I have doubts about the focal point(though I'm willing to be proved wrong)Though perhaps quick evaporation of the droplets could cause drying out? If I'm right all I can suggest is be careful with watering though even established large plants suffer with this at times. As a side note I've realised that I always worry at the slightest imperfections on the plants,the foliage after all is the main focus for us and it's good to pay close attention.However you only have to walk in the countryside and look at the native plants to realise they're all but perfect...many pests,chunks out of the leaves,fungi,a lot of rust,broken branches and die back.Sometimes I think I over react(particularly with watering)and it's probably best I don't meddle so much ha ha.
Hi Houzi, Thank you for your input. I started to see more maples (even American one) have the same issue in my area when we do our walking in the neighborhood. Two years ago, I sprayed the fungicide when they just leaf-out and again when they all opened. It showed a bit less spots than this year. I was wondered if Bordeaux mix would helped. I bought the ingredients but was told not to spray now until the falls after the leaves are dropped. One local JM nursery told me I can tried spray the seaweed 'kelp' to help strenghten the tree and decrease these fungus, I may try it this falls. I have the 'fairy hairy' with long thin leaf so after the spots attacked then the sun shines to them, they are burned easier than w/o the spots. I wish someone can share how to treat these spots cause they are all over my trees this year. Thanks again.
