Anyone know what happen here?

[Bonds Guy]

So my Prunus mume ‘rosemary’ have some serious dieback, but I’m not sure what caused it. It looks like some time during the winter it tried to exist dormancy, but my other ume tried as well however, there’s no dieback on that one. I sprayed both with fungicide at least 3 times throughout the winter so I assume it wasn’t a fungal issue. One key difference is this mume is have about 2 inches of exposed cambium (I forgot to take a picture of that area) so perhaps that caused the dieback?

 

[Forsoothe!]

Any opening into the heart of the tree is asking for problems with most species. Prunus is worse than most. Many of us seal wounds greater than pencil diameter. Where have you kept these over winter?

 

[Bonds Guy]

Any opening into the heart of the tree is asking for problems with most species. Prunus is worse than most. Many of us seal wounds greater than pencil diameter. Where have you kept these over winter?

Its potted in a pond basket and I buried it in mulch. The area where it was buried receives almost no sun during winter. I figured that would keep it from existing dormancy too soon

 

[Forsoothe!]

Its potted in a pond basket and I buried it in mulch. The area where it was buried receives almost no sun during winter. I figured that would keep it from exiting dormancy too soon

I'm not sure one way or the other if that theory works, but I think you'd get less bud development without good sun. Maybe others have experience with that. I keep everything in full sun so I don't have to re-introduce them to the sun after they begin to leaf out in the spring. I seriously doubt that spraying 3 or any times during the dormant period is necessary, although a dormant spray just before bud-break is common if you have special problems with bugs or disease. If you can see that the die-back ends at good wood and are able to cut back to good wood, I'd do that now and splash on some hydrogen peroxide before cutting and then on the cut before sealing. Then use a dormant spray just before bud-break. (I wound seal any wound whenever you find the wound.) Better safe than sorry, especially with Prunus. Good Luck.

 

[Cadillactaste]

I also do a regiment for fungal during the dormant season. Mulched outside...this isn't critter damage is it?

I have gotten hard frost damage where I've had splitting on landscape trees/shrubs. It tends to heal over and swells in that area where it has had damage. I've not suffered dieback from it.

 

[sorce]

That one Does look like a squirrel bite.

Sorce

 

[Forsoothe!]

I also do a regiment for fungal during the dormant season. Mulched outside...this isn't critter damage is it?

I have gotten hard frost damage where I've had splitting on landscape trees/shrubs. It tends to heal over and swells in that area where it has had damage. I've not suffered dieback from it.

Splitting is common on JM in spring on the sunny side when a hard freeze follows a period of warmth making the sap flow. I try to hide the trunks of JM now in the landscape by planting them where the S or SSW facing trunks are shaded by something so the sap doesn't get started too early. Still a crap shoot anyway. I lost a 15 year old A.p. species and 10 year old Sango Kaku after split trunks weakened them and the two winters from Hell in 2011 & '12.

 

[Bonds Guy]

Here’s a pic of the wound.



This wound was there when I got it. As for the smaller wound it could’ve been caused by a squirrel. I been at war with them since spring of last year.

If you can see that the die-back ends at good wood and are able to cut back to good wood, I'd do that now and splash on some hydrogen peroxide before cutting and then on the cut before sealing. Then use a dormant spray just before bud-break. (I wound seal any wound whenever you find the wound.) Better safe than sorry, especially with Prunus. Good Luck.

The buds have already opened. So I was thinking to use the systemic fungicide and pesticide (infused & imidacloprid) Bjorn recommended in his latest youtube video

 

[shinmai]

I agree with Sorce. That looks like a squirrel or chipmunk chomp to me.

 

[Cadillactaste]

Splitting is common on JM in spring on the sunny side when a hard freeze follows a period of warmth making the sap flow. I try to hide the trunks of JM now in the landscape by planting them where the S or SSW facing trunks are shaded by something so the sap doesn't get started too early. Still a crap shoot anyway. I lost a 15 year old A.p. species and 10 year old Sango Kaku after split trunks weakened them and the two winters from Hell in 2011 & '12.

All my landscape have frost damage in the branching, that looks similar to your last photo.

 

[Forsoothe!]

I had a tree branch that was right outside my bathroom window, and watched from about 5 feet away a squirrel bite a vertical twig, break it and strip it down so it came to a sharp point and pick his teeth with it. It took about 3 or 4 minutes and I secretly watched the whole thing. I was surprised that he was smart enough to understand the concept of making a tool to do a particular job.