Help with a sick mugo pine

[TorroK]

Hi Guys,

New to bonsai. Got a relatively young mugo pine in the late summer. As my first bonsai project. Havent done much to the plant other than some wiring and a repot. Thought id leave pruning and removing some excess branches to the coming autumn. For context its a mugo pine. Maybe 20cm in height. I have it wrapped in a ”plant blanket” that was sold in my nearby gardening store. I live in an extremely cold climate so i was scared the roots would freeze. But up untill now winter has been relatively ok max -10c maybe. Anyway my pine has developed a white moss looking thing over several branches. Im guessing its a fungus. Ive realised i may have watered it to much now thats its been colder. Maybe 1 time in a month or 3 weeks maybe? But just wondering if anybody would have any insights as to what the fungus could be and how to deal with it. The pine is on my balcony so experiences the outside weather but its glassed in so no wind. And pretty good sunlight exposure. Its so north here that theres not many hours of sunlight though. It seemed okay last time i checked on it but this developed in the last month. Thanks for any insights in advance!

 

[Paradox]

Hard to see exactly but if they look like little fuzzy little cotton balls, its wooly scale or adelgids.
If they look more like little white shells, its hard scale
Either way, you need to kill them.

Id suggest doing it in an outside shed or garage.
You do not want to treat those in the house

 

[TorroK]

Hard to see exactly but if they look like little fuzzy little cotton balls, its wooly scale or adelgids.
If they look more like little white shells, its hard scale
Either way, you need to kill them.

Id suggest doing it in an outside shed or garage.
You do not want to treat those in the house

Thanks for the reply. It looks like fuzz with some more opaque white spots on the needles. Another picture attached. How can i go about killing this? I just saw some blackening so i guess its been abit too cold as well

 

[Kodama]

Havent done much to the plant other than some wiring and a repot.

These are actually huge actions to the plant and has surely weakened it to possibly be susceptible to what condition you find. I've heard on some evergreens that only one insult a year. Good aftercare from repotting is important but then too much protection can also be bad. Do you have it in a well ventilated area, not windy but good airflow? Hope you find the cause and solution.

 

[The Barber]

Can you get clear closeup photos of the fuzz and white spots?

 

[Paradox]

Thanks for the reply. It looks like fuzz with some more opaque white spots on the needles. Another picture attached. How can i go about killing this? I just saw some blackening so i guess its been abit too cold as well

Black could be a fungus that comes from the sap being oozed out as the scale/adelgids feed on the tree.

You kill them with an insecticide spray like Sevin.
Again do not do this inside your house.

 

[Catagonia]

I killed a couple of Mugo pines before I got it through my head that the roots need to stay in the soil they grew in to get the benefit of their symbiotic midichlorians or whatever they are called. (OK, I looked it up, mycorrhizae.) I have one doing ok now. I moved it and its soil into a larger pot partly filled with bonsai soil. I’m hoping the good fungi will spread into the bonsai soil so I can eventually shift it completely without trouble.

 

[Shibui]

I live in an extremely cold climate so i was scared the roots would freeze. But up untill now winter has been relatively ok max -10c maybe.

It is best if you can add a location to your profile so we can understand how cold 'extreme cold' actually is. City or state is usually enough to get a feel for the climate without compromising your privacy. Your location will also give us more clues on things that might help or things that might be wrong. Different things work in different parts of the world.

Better photos needed to diagnose the problem. So far both photos out of focus so I can't see the white properly.
I think I can see grey fluff on the branches which I suspect is some sort of mould which could be growing because the air is too still and too humid. Remember that mugho pine is from mountains in Europe so this tree should be able to cope with pretty cold temps without extra help.
Have you wrapped the entire plant or just the pot?
A photo of the entire plant and pot might help us to spot some other factors you may not have considered.