AusBonsai

Went away for a few days and two of my A. Palm. have wilted, green stems losing colour and trunk of one looking grey. I'm afraid it's fungal and I should just ditch the plants and mix.

Burn them now?

Hi there,

Where are you located?

Have you recently fertilised?

Where are you keeping them?

What soil are they in? (if a store bought mix - where from?)

How much water are they getting/not getting?

Any other relevant info you can provide?

Regards,
Mo

Soil looks like a good mix.
I have had this problem several times in the past. I agree that it is fungal and trees do not recover well.
Cut away well below the affected areas or discard the tree completely. Fongarid is a good product but I think it is too late for this tree.
I have started to spray with diluted lime sulphur when the maples are out of leaf. A light spray on the trees follewed by a heavier spray on the empty benches before putting the trees back.

Where I live, lack of sun is a major influence on my species choice, and maples are not on my welcome list. Because of the lack of sun, the ones I have always tried over the years end up looking exactly like the pic of yours dying... due to periods of excess rain and not enough sun or too much shade causes them root rot which starts at the base with Japanese maples, and goes up inside the trunk. The first sign is the wilting leaves and the blackened branches. Once you have it, you can pretty much almost certainly forget the bonsai. If this is the problem, RidRot might be a thought, but generally looking at your photo it is too late.

If the roots are not allowed to get dryish, and there isn't enough sun coming in, maples will generally always die.

Of course, fungal diseases are not much fun when you add this to the list of vulnerability to acer palmatum. I prefer a few other maple varieties as they are less reluctant to just cark it willy nilly. From my experience, trident, taiwan and ginnala are evolutionarily better equipped for my area. Though I do love palmatum, it is unfortunate that they get so finicky. And the red leaf maple of palmatum, omg, what a nightmare they can be without adequate sun. Dishojo can be good, and so far is probably the best luck i've had with acer palmatum varieties.

I've had quite a lot of this with old maples - I was told years ago to be scrupulous with sealing cut roots with cut paste or grafting paste, didn't do it, and now I'm paying the price. Fungal infections get established within the tree, and any little stress is enough to send them over the edge. Once you can see the leaves failing, nothing works. I'm trying the lime sulphur in winter, I hope I can at least keep some…

My mix is free draining, I don't over-water, it just seems that maples are more susceptible to fungal diseases.

Gavin

Thanks everyone. The mix is 60% Zeolite ( Vitapet Purrfit) and the rest Osmocote Orchid mix (mostly pine chunks)

It is too hot in summer for Japanese Maples here.

So I have them in a shady spot in the garden sitting on gravel filled trays.

It looks like my (latest) mistake is leaving them there in Autumn. It's been raining on-and-off now for two weeks

Ergo - the rest will be going back into a sunny position for winter. (Rain, rain and more rain between now and September)