Apple experts - need your help

I posted up on the diseases thread, and we identified I earlier had woolly apple aphid, but I don’t believe that is why I intermittently have branches dying.

3 years ago, there was a lot of hail damage, and I think this 25’ apple had fireblight. I’m not sure if that is still what is going on here, or if it is possibly lack of watering (not trying to produce fruit this year, as the tree is getting grafted over). This happened last year, as well.

Can anyone suggest why I randomly have branches dying throughout the tree? I grafted a dozen varieties this year, and am a bit concerned they will be hit.


1 Like

I’m not a huge expert in apples but I think fireblight is the most likely reason.


Yup, fire blight. It’s probably fine just to cut out small wood strikes. On larger wood the verdict it to leave stubs after cutting back to healthy wood and then remove the stubs during the dormant season. This is supposed to reduce the chances of it reaching bigger wood where it becomes a huge problem. However, in my area in the northeast on big apple trees, strikes are most often limited to small shoots- no matter the treatment or lack thereof.

Cicadas ?

FB strikes tend to ooze and there is no physical injury as there would be with cicadas.

Thanks, all. I appreciate you weighing in! Definitely not cicadas, and fireblight fits with the history and the area and timing.


Since this has been going on for (at least) a few years, and given how it polka-dots around the tree, do you think it may be systemic, already, and only cropping up in June/July? That hail storm we had in June 3 years ago was hail to 2.5", and best I can tell, that is when it all started. It went a year and a half before I could get to pruning the tree.

If systemic, is it something the tree can overcome in time, or just something that will plague (but not kill) the tree and be managed annually?

I don’t think FB survives in the tree and creates shoot strikes from bigger wood, I think it moves the other way around. I’ve had plenty of sites where FB appears and even when I don’t cut out all the FB cankers it doesn’t return, at least for 10 years and counting.

FB is a very mysterious disease that behaves in ways not well understood, at least by me, but I think by pathologists as well. Why when conditions are perfect it sometimes only strikes apple trees when nearby pears are untouched.

One thing I know for sure, trees are only killed by it when it enters big wood and you know it has because whole scaffold branches dies all the way to the trunk. I manage a Bosc pear that survived such a case and grew for 5 years completely regaining its shape and bearing crops. This year it is almost dead, but I don’t know if it has anything to do with it’s former issues with FB. I doubt it.

Thanks for sharing your insights on this one, Alan. I will keep trimming it out and see what comes of it; good to hear you don’t suspect it’s source is the bigger wood, and thanks for sharing what happens when it does enter big wood.

1 Like

Note that the various cicada outbreaks are not near Colorado, the location of rossn.