I don’t see any good resource for purchasing Ambrosia pears, wonder why it isn’t more popular.
Gurney’s has it. I have not really looked for it otherwise. I have a tree growing.
We had a mature pear tree (an unknown variety, somewhat similar to Bartlett) growing in our yard from 2007 to 2013. One year it was hit hard by fire blight. I planted Ambrosia in 2010, and thankfully it hasn’t had a single fire blight strike so far.
Interestingly, my apple trees have had fire blight for the past two years in a row, but Ambrosia, Bell, Potomac, and Harrow Crisp have all remained completely fire blight–free. Bell, Potomac, and Harrow Crisp are growing only about 20–30 feet from the infected apple trees, while Ambrosia is across the yard, roughly 100 feet away - if that means anything.
I would definately graft a branch of karls favorite on both. It is the only choice for those 2 pears that will get you a heavy crop of pears. I’m not saying not to plant the karls favorite aka ewart tree but I suggest if you do it is very close to both. Most pears trees won’t properly pollinate either tree.