You should cross-post this in the Trees forum. I know treebarb will likely see this but I also know there are a few really knowledgeable helpful people on the other forums that won't look here in Rocky Mtn forum.

I tried to cross post and every time I tried to add a tag, the site would crash. It happened at least six times, both computer and phone. Should I just copy and paste and mention that it’s cross-posted?

We had an arborist out about a month ago to check our partially uprooted tree and he noticed that our crabapple had some fire blight. He said to wait until the leaves drop in the fall and the leaves on the bad branches will not fall. Cut those branches off then.

Ok, I’ve posted in fruit and orchards, so hopefully that will help.

So, it seems like nobody so far thinks that I need to cull the trees to protect my other young trees in the area?

It depends on how much of the trees are affected. A few branches might be manageable. If the majority of the tree's branches are affected, it might be better to cull. You might be surprised how much you can prune off a fruit tree and have it come back, though.

You can preventatively treat the surrounding pear, plum and cherry with a copper fungicide. Bonide is a concentrate that you could pick up at most garden centers. Read up up on it though, with the little ones running around it could be a challenge to spray and allow for dry time.

If you decide to cull, look for fireblight resistant varieties like Golden Delicious to plant.

What I'm reading is that fireblight is an above ground disease, so you can replant in the same spot. It's spread by wet conditions which we haven't had, but also by driving, hard rains and hail which we certainly have had.

Fruit trees are challenging. If you look into the spraying schedules that are recommended, dormant oil in fall/winter, pre flowering spraying, post flowering spraying, etc. it seems pretty daunting. I did it for a few years, then decided to just let it be. I've only had one incident with fireblight, one branch on an apple that I caught early and pruned out. I am surely not an expert. You kind of have to decide if you're willing to use chemicals or if you can live with what comes.

We have plum, peach, apple and pear tree in our yard. Have had small instances of fireblight on all of them in the past which I handled with pruning the infected branches. All but the pear tree have had only small infections, but the pear tree gets it every year and this year in particular is the worst, which is a shame because it finally fruited! Since I've read that it can spread to the other trees through birds/bees/wind, and pear is the most prone to fireblight, have decided to cull it. I probably won't plant another tree there so as to give the others more sun and air. May plant something smaller, like an dwarf alberta spruce.