If you treat your trees regularly with a fungicide as OSU says to do, you ought to be able to keep them alive. Cedar Apple Rust is not a persistent problem in my area because almost nobody near me grows apples or crabapples, so I rarely see those globs of orange hanging in the trees. I have two neighbors who grow apple trees, and they've cleared away cedar trees (to the extent that they can) so there are none too close to their apple trees. In both cases, their particular sites are somewhat sheltered from the prevailing wind and that seems to help their trees. I imagine they spray their trees to keep them disease tree, though I've never knocked on their doors and said "Hey, do you spray your apple trees?" (grin)

I do not think CAR is an annual problem in much of OK, but maybe it depends on where you live. We almost never see it here in the dry years (which we have plenty of) but will see it occasionally in the spring that follows a wet summer. I believe the infection occurs in the wet summer, but you don't know it is there until the following spring. If you are in a part of OK that generally is wet every year and has higher humidity than what we normally here in southcentral OK, you might see it more regularly there than we will see it down here.

Do you know why your cherry trees died? Cherries do need very well-drained soil.

Just realized I didn't check back in on this. I've treated with the fungicide. It say to treat the tree three times over about 2 weeks. Their are only about 6 feet tall, so its quick work.

On those cherry trees, I'm pretty sure it was the clay soil -not well drained-- that did them in. Very tough to find a suitable place near enough to water, away from cows, etc.