Some trees are more resistance than others. I have had it in my orchard on a number of trees, yet other trees were not affected. At times I have had fire blight so bad I could see the bacterial ooze dripping off the blossoms. But, as mentioned no infection on other trees. If I felt like I needed to do something, my first action would be to do just what you suggested. I have thought about trying to remove the canker tissue, but never have tried it. Canker blight that overwinter can cause water sprouts to become systemically infected by the fire blight bacteria if its on a nearby overwintering canker. If I cann't remove the whole branch because the canker is on the trunk, I just leave it alone. However, I do spray the trees with Kocide (copper) along wih my dormant oil spray and maybe it helps, but I am not sure it does much for the fire blight. There is a lot of information on fire blight and all of it does not agree. Studies have been done where it has not helped even to cut out the first strikes, just leave it alone until you do your dormant pruning and then cut out the dead branches. I used to put a lot of time and energy into fire blight, but now I take a more casual approach to it. I have had a lot worst looking trees than yours and one time ordered a new tree to take the place of the fire blighted one, just to pick a couple box of apples off of it this summer. I sprayed painted all the strikes with red paint, then pruned out all the branches during my late winter purning. The tree looked like Charlie Brown's Christmas tree, but is now doing well. Go ahead and try what you suggested. Unless you completely girdle the trunk, it should not harm the tree too much. Use it as a learning experience. See what works and what does not work. I have had some trees die from fire blight, replaced them and they again died. Now, I avoid that particular variety.

Pears & Quinces are actually much more susceptible, as well as Pyracantha and many of the Photinia family (our lovely Toyon for example) Um, Photinia isn't a family. All the plants you named are in Rosaceae except Heteromeles, all Rosaceous plants are susceptible to fireblight as the OP stated. AFAIK fireblight doesn't attack citrus or non-Rosaceous plants. The bacterium can persist for more than a season in favorable conditions and doesn't mind spreading. So if present you should watch your other plants and catch early. Use proper precautions when doing so. Dan

Alright a few more pieces to the puzzle. your arborists mentioned borer and orange sap. the primary borer that attacks cherry trees is the peach tree borer which almost always affects the very bottom of the trunk of the tree (maybe 12 or less inches from ground level) now there are occasionally borers or bark beetles that will enter the tree higher up but in my experience they are secondary or advantageous pests usually affecting trees or individual limbs that are already highly stressed/damaged due to some other cause. That being said, there are other factors that can cause this orange sap type of bleeding...one is called gummosis which is an abiotic (meaning not caused by insect or disease) issue where sap is exuded out of the trees lenticiles, these are the small horizontal "dashes" in the trees bark. this can be caused by mechanical (physical) or winter injury, excess fertilization, drought stress etc. and there is no cure other than to keep the tree as healthy as possible and let it grow out of it. The other cause for this bleeding is, as mentioned above, bacterial canker, the most common of which is called Pseudomonas syringae. one way to potentially tell whether you have gumosis or bacterial canker is to go to the affected (bleeding) area and press firmly with your thumbs and feel for a soft or sunken area immediatley around the sap. if it feels soft/mushy or sunkin in then you are probably dealing with a bacterial canker, if not it may simply be gummosis. this little push test is not 100% accurate of coarse but sometimes it works. So first off, where are these " borer holes" located (down at ground level or higher up in the tree?) Second, does this orange sap appear to be coming out of the lenticiles or is it just coming straight out of the bark. Third, is the area around the bleeding soft/mushy or sunken in. I don't think planting a few bushes around the tree is of any real concern, but another thing that i forgot to ask before is if by any chance the soil around that tree has for any reason been compacted lately (within the past 2 or 3 years) like heavy vehicles driving near it etc. hope this helps, Ron R. Here is a link that might be useful: bacterial canker

Hi all. Thanks for the help. Location is Eastern Washington State, US. The climate is very dry here (although this year the spring was a bit early and wet) so as I understand it the region is at low-risk for fire blight. The trees are more or less isolated. There's a large ash tree nearby, a few conifers about 20 yards away, but other than that it's a 100 yards to any other trees (apart from the 3 apples). The trunk discoloration, etc. did start this year, or at least if it were there last year it was very slight and didn't affect any leaves. I'm always passing by these trees and they get looked at relatively often. I looked up fire blight before originally posting but couldn't figure out if this was it. The problem seems to have started centrally, which confused me, and I didn't see any obvious bent new shoots (shepherd's crooks, says the 'net). On the infected shoots it seems the top is flat, almost like it's been pruned. Attaching more photos in another post.