Sorry folks, but I object to the thesis of this
thread. The easiest fruit tree varies enormously from place to place, and often the easiest fruit is not a tree. I skimmed the comments and every single suggestion I saw is something I wouldn't recommend for various reasons. I live in WV zone 6. I do have a sour cherry tree, which gave me a bumper crop once, lighter crops a few times--but only if I put a net over it. Otherwise the birds get most of them. We have both wild persimmons and some grafted varieties that are bigger and nearly seedless. They are extremely sweet and flavorful, but the wild ones are a bit hard to use what with the many big seeds, and it can be hard to tell when they're ripe--too soon and they're astringent, too late and they get funky. Pears are subject to fire blight, especially the Asian pears, but there are varieties that are highly resistant. I have Potomac, which has never gotten it and Blake's Pride which gets it lightly--but has never produced a pear (I planted these in 2009). I used to also have Moonglow, which produced a few pears but then succumbed to fireblight. I love peaches but they get hit with late frosts more often than not, and are subject to brown rot. I haven't tried plums here as I had no success with them in another place. I have a fig which I cover with a sheet every winter after filling its cage with leaves; it survives and comes back but on fresh
wood every spring. This year I got 14 figs, a record. I have three apples from the same planting--Goldrush is the standout for heavy production almost every year. This was a bumper year but the wretched squirrels, who had a population explosion this year, took them all. I put in two goumi bushes--this is a relative of the evil autumn olive, supposed to be non invasive and the fruit is bigger. I got some fruit the second year and several pounds this year. The only downside is what to do with a zillion berries with inedible pits--I boil them into a liquid and make a sauce. I planted two cornelian cherries about five years ago--they are so slow growing that I haven't anything to report about the fruit yet. My thornless blackberries have not yielded much (two years after setting out) but other people here have had heavy crops. Blueberries require an extremely acidic soil and must be netted, but i have sometimes had success with them--feeding them
coffee ground and
apple pomace helped. I tried American highbush cranberry, which made a fast-growing ornamental but the few berries are not edible--I think I have the European one. i tried currants--they languished, seemed unable to tolerate hot summer weather, produced a few fruits but didn't grow. What I recommend if you want reliable fruit every year, is strawberries. They're a fair amount of work but even in years when you lose half the crop to drought or rot, you have the other half. I've never had to cover mine. Despite the fact that the plentiful wild rapberries and blackberries tend to be full of disease and not very fruitful, the cultivated rapberries in my garden do pretty well.And I'd say apples are the most frequently successful tree here.