Chinese Elm

[Clint]

I recently got a new Chinese Elm which has been doing well. Yesterday I noticed these red/brown spots on a few leaves and am quite concerned. I have been through my books and various websites and have found very little that resembles this. It lives outdoors and gets a good amount of sun.We recently had 3 or 4 rainy days though with no sun.
Any help or advice would be greatly appreciated.

[shibui]

Hi Clint and welcome to Ausbonsai.
Chinese elm are often evergreen up there in warmer climate. Do you know if these leaves are new this season or left over from last year? They are all on terminal shoots so I guess they are new this spring which would rule out old leaves dying off.
How much of the tree is affected and is it localized or general all over? Sometimes clues can be found just by the location and extent of any problem so an overview of the tree and its location might just ring bells with someone else so a couple more photos of the whole tree might help.

I have not seen that same pattern of browning leaves but my next guess would be sunburn. Any chance the pot may have been a bit dry one day in the past few weeks? Had any hotter than usual days? What is your watering schedule and what sort of soil/potting mix is the tree in?

A third guess would be some nutrient deficiency or toxicity but the pattern does not really match any that I am aware of. How often do you feed the tree?

Fungal infection is a final possibility. A couple of rainy days is not usually enough to set off fungal problems. Usually takes long term humidity or wet conditions.

[Clint]

Thank you so much for the reply.
They are only on one side of the tree. The side that faces the sun. It gets sun from early morning til around 1:30/2pm. They appear to be only on the newer branches.
I don't think the pot would've been hotter than usual, definitely wetter. We had 3 days of heavy rain with intermittent sunshine and extreme humidity. I only water when it needs it, using the chopstick method and it gets fed very 2 weeks with powerfeed. It is in a fast draining soil mix that I purchased from Aust Bonsai Grower.
I will attach a couple of more pics of the overall tree. I have removed the tree from its usual spot to take these.
Thank you for taking the time to give me advice. I really appreciate it.

[shibui]

Younger leaves and damage only on the sunny side tends to point even more toward sunburn. Not sure how or why. Usually the sun cycle changes slowly so the leaves can adapt to the slow changes as days get longer and sun a little hotter each day. Sunburn usually happens when a tree is shifted from shade to sun quicker than the leaves can adapt but you seem to indicate that it has been in the same place for some time so unless something around has changed that allows more sun on the tree I cannot explain the sudden leaf damage.
Your watering and fert are both appropriate. Well done.

A few damaged leaves is not so unusual for a bonsai, especially in early days. I would not be worried until more leaves are affected.
Latest photos show a lot of long new shoots so the tree could be trimmed if you want to and that will remove most of those brown leaves for now.

[Clint]

Thanks again for your time and advice. I really do appreciate it. I will just keep an eye on it to make sure it doesn't increase. Fingers crossed

[Raging Bull]

Hi Clint, if it's any help, I'm on the Gold Coast and have had several Chinese elms for a few years now and never had problems with rust, fungus or disease with any of them. They are quite hardy and grow well here.

[Clint]

Thank you. That does help, puts my mind at ease. Appreciate your reply