AusBonsai

Hi there guys,
I was wondering if anybody could identify whether my maple is sick/infected? Or what I should do to get it back to some health.
There are these black dis-colouration on its trunk and branches, and it has not leafed out yet all spring.

Thanks for any help you can give.

Josh

I had the same problem with a large maple that I had.
I never did find out what caused the problem.

After a while it began to weep sap and died.
Good luck with yours.

Sorry to tell you this, but your tree has died from the roots up. It's one of a dozen root rot fungi, such a pythium, or phytophthora.

Wet and warm weather brings it on, especially if you have recently repotted the tree.

Paul

Is there anything you can spray/dip/apply preventatively? From my experience all the fungicides I've tried don't work once it's taken hold.

Gavin

Hi Josh,
Using soil with good structure, good re-potting hygiene, sealing large cuts below soil level, re-potting as the buds swell in spring, not before or after and evenly damp, not over moist soil post re-pot are helpful in avoiding fungal problems in Japanese Maples at this time of year. Air circulation around the pot is beneficial, over congested benches where water can pool can be problematic. Later on in the growing season, it's probably a good idea to avoid watering the leaves if at all possible.

Cheers,
Mojo

Well that sucks!! Poor little fella was struggling compared to the other trees I have.

Thanks for all the tips guys. I think I may have been over-watering since I repotted the JM earlier in September. My other maples appear to be health at the moment growing in the ground. Maybe another excuse to buy a replacement tree. I've got 2 JMs and a trident. Wouldn't mind another maple .... But of another variety. If anybody has a fav type would love ideas.

Have you scratched the trunk in several places?
Is it green underneath?

Whilst I think it may be cooked as per the sage advise given. Perhaps a repot into a looser mix and see what happens if there is a hint of green?

Also the roots may further give clues as to your trees health (or lack of).

Cheers.

Reading your symptoms and looking at the pic, I would say over watered.
This is generally the most common way to kill a Japanese Maple.
Not enough sun and too much water = bye bye japy.

If you are prone to over caring for your bonsai - by that I mean over watering - then I would suggest something like Acer Ginnala. They are more resistant to rot and wet soils. Problem with JM is, once the rot gets up from the base of the tree, it goes up in the trunk, and nothing will save it, it'll be dead in a few weeks. The branches begin to darken, then blacken and it is all over.

A tip is... don't water the soil when it is still even slightly damp, the soil needs to not stick to your finger, even an inch down into the soil, otherwise you are overwatering and the roots can't breathe and they rot, thus not feeding nutrients to the tree and are unable to absorb the water, thus it produces the same slow likeness as needing water, and thus the real problem starts, when a novice will then again water the plant assuming it is drooping from lack of water, and it just inevitably dies soon after as this repeated cycle continues.
Also, good drainage can do wonders for their health. Japanese maples will often tell you when they need water by looking at them, but that kind of tough love, requires daily attention, thus it is best to just make sure it has good drainage, and that you haven't compacted the soil tightly after repotting etc etc.