Sickly maples

[apr]

Hi all

I've purchased 4 maples from the same garden centre and all have either died or appear to be - not quite sure where I am going wrong with these as I have several others from different places that are all thriving.

There were a few buds that popped and leafed out but quickly look like they've died.

Verticillium wilt ?

Thanks

 

[BonsaiMatt]

Verticillium wilt ?

Very possible when you see a tree completely collapse like this + black stems. Don’t reuse that soil, throw it out.

 

[Shibui]

The black bark on the trunk is a give away. Way too late to do anything when the black is completely around the trunk.
It seems to be much more common where pots are sitting on the ground over Winter and early Spring which means soil and roots stay too wet. Rare when the trees are on benches with more air circulation and better drainage. I have occasionally had trees recover if the black had not spread and I managed to dry the soil and keep it barely damp until the weather warmed up.

It is possible the infection is from the garden centre but more likely related to subsequent care. When did you get them and where have they been since?

 

[apr]

The black bark on the trunk is a give away. Way too late to do anything when the black is completely around the trunk.
It seems to be much more common where pots are sitting on the ground over Winter and early Spring which means soil and roots stay too wet. Rare when the trees are on benches with more air circulation and better drainage. I have occasionally had trees recover if the black had not spread and I managed to dry the soil and keep it barely damp until the weather warmed up.

It is possible the infection is from the garden centre but more likely related to subsequent care. When did you get them and where have they been since?

Makes sense

I got them in summer last year. Kept in pots overwinter on the ground.NE scottish winter, wet wet wet. Repotted in spring and the garden centre substrate was pretty wet and manky.

One of them is a kabaduchi attempt, saplings were beginning to fuse and that one has been in bonsai soil and off the ground a year. I'm wondering if it is a bit weaker and therefore succumbed as well.

Deshojo from a different nursery was quite healthy all last year, substrate wasn't that wet and was repotted this year into bonsai substrate. Also kept off the ground. Hoping it hasn't spread to this one too.

How easily is verticillium spread between plants ? I have isolated this one in my garden, hoping it hasn't spread to my others which are all looking healthy.

 

[Shibui]

How easily is verticillium spread between plants ? I have isolated this one in my garden, hoping it hasn't spread to my others which are all looking healthy.

Not sure how easily this problem spreads. Most advice is certainly to sanitize tools before cutting a new tree and many recommend disposing of potting soil from infected trees. Isolation of infected plants is also recommended. Not sure if any of these measures are actually necessary but in the absence of firm evidence I think it is wise to err on the side of caution.

I've had no further spread when conditions are improved so I suspect it is always present but only infects plants when conditions weaken the tree or favour the infection.

 

[BonsaiMatt]

How easily is verticillium spread between plants

It lives in the soil. Can probably spread from splashing water while watering, so keeping them separate is a good idea.

 

[Rivian]

You should first verify whether it is Verticillium or not. Cut through a 2+ year old stem that shows signs of disease above it and post the cut surface. Verticillium would cause olive discoloration in the sapwood.
Wetness related disease could just as well be Pseudomonas.

 

[apr]

Thanks

Will isolate and see what happens for the rest of the spring/summer.

Any suggestions for a bactericidal treatment ? (Would be good to have one anyway even if these trees are gonners)

 

[bwaynef]

You may want to look into Pseudomonas as a culprit, rather than verticilium. I see @Rivian just mentioned that as well, so I'll throw a vote there. Vert discoloration in sapwood is different colors in different trees, so any discoloration would be indicative. Note though, the discoloration being in sapwood, not outwardly. Pseudomonas fits better with the symptoms and timing.

 

[rodeolthr]

If I had to guess, I would agree with @bwaynef . Here in the PNW, if maples sit in heavy, wet soil over the course of winter, you're asking for dead trees come spring. The damage doesn't show until the weather warms and they "start" to leaf out.

 

[apr]

Thanks all

I've isolated them for now. The Katsura is dead for sure the bark is soft, nothing green around the trunk - will leave everything else the rest of the spring just incase and then do a post mortem.

The deshojo is still alive, can't see anything obvious, no squishy cambium, no black spots, no obvious discolouration of the bark, soil is damp not soaking etc,

Doesn't seem worth spending loads of money on getting bactericide for cheap nursery stock, but has made me think to be more cautious in the coming winter with some preventative measures and general pest/fungus control

 

[apr]

So the Katsura, bloodgood and my bloodgood clump style are all dead and have been isolated and thrown away.

My deshojo I can't tell if it is trying to push growth but it still hasn't. There are fresh looking buds, albeit tiny, that are bright red/pink and look alive. So far I've kept it in a sheltered spot and making sure it's moist but not soaking.

I also have a Sangu Kaku, and another airlayered maple sapling, both of which I think have been sun damaged, or rather, the roots have possibly cooked. Both currently sheltered, but we have had unusually hot and consistent temperatures in Scotland this May.

I'm also beginning to think my deshojo may have leafed out in the better weather, then been hit hard by a week of temperatures in the single figures.

I am wanting to get some slightly more developed trees but a bit reluctant at the moment as I don't know if it's back luck with these or I'm just bad at maple horticulture still ?

 

[keithl]

I have some trees with what I think is Pseudomonas as well right now. Came in on an Ume I bought. I didnt know what it was originally but now looking back, the leaves had clear signs. I lost that tree and about 20 two year old rooting cuttings over winter (they all have areas turned black). I also have one japanese maple that has a big black ring and the leaves are all wilted. I also lost a whole bunch of tridents that have a little black on them so I assume its the same thing.

I couldnt pin down what was happening but I think I figured it out. I think what happened in my case is we had a huge amount of cicadas last year. They caused a lot of damage to many of my trees, and most of trees with cicada damage are the ones that died. Normally cicadas dont kill trees, but there is a clear correlation. Now thinking about it, I think those wounds allowed the spread of the disease.