Well, to return to the original question-"Should I try to have them grow like a peach tree with 3 or 4 main branches? Or do I need to do something different?"- I'd say do something different. Open center pruning was a response to brown rot on peaches in the south- it let sunlight and air circulation reduce the humidity that ruined the crop. The only reason I can think of to do it with apples pears and plums is that you don't like ladders. Modified leader is really multiple leader- you let two or three scaffolds turn upward and compete with the central leader. Eventually, you top them all off. There's more pruning of crossing branches than with with central leader, but you'll get more production out of apricots and plums with the additional branching, and pears just have a natural tendency to grow this way. Bart, you said "some (especially some apples) have 4 or 5 branches radiating out of the trunk on a few different levels so there may be nearly 20 branches spaced in 18" of vertical trunk." I'd take most of those off. Even if you later cut out the leader, you'll want at least 6" between each branch. And you'll eventually cut off everything below 3 or 4'.

We don't water it, as we get a mild amount of rain here. Not too much, but just enough to keep the soil a little moist. Our soil pH is 6.5. We have horrible clay soil that, when it gets dry, is like a rock. We don't have any soil imbalances that I know about. We tried some miracle-gro fruit tree fertilizer stakes that we got from our local nursery. The leaves don't have any mottling or spots or other imperfections. They are a light green color, as most plum tree leaves are. They look like these leaves http://t2.gstatic.com/images?q=tbn:ANd9GcRg2VR-rKLwEAAPVEqooo6rV1YWFDcYIQdquzJJWePLH4-x5OkZ Except without the plums, obviously. Now about the apple trees. The bigger one (GD) got the same fruit tree stakes but to no avail. Its leaves have cedar rust, but it is because our neighbors have juniper and cedar trees. It never affected the 6 huge and beautiful McIntosh and GD-Mutsu Hybrid trees we had at our old house, which is about 2 miles away from our current house with the same weather and soil conditions, and the trees were in the exact same amount of sun. There are no visible signs of pest or disease on any of the trees. the only things that have ever bothered them are japanese beetles, which we have only had twice, so that doesn't seem to be the problem. Our average temperature throughout the year is around 79. We get around 40 inches of rain per year and all the trees are in full-partial sun, leaning more towards full. What I am wondering is, do nurseries that supply local nurseries and garden stores with fruit trees, put some substance on/in the trees to force them to produce fruit? It seems like every tree i have ever had, produces fruit the very first year I plant it, then it starts up again 2-3 years later. Do you know the answer to this? Thanks again. Lydia

Temperature during pollination is important if this has already been stated I am sorry. I've read some fruit trees can set fruit with own pollen if the temp is warm out. I've had 3 terrible cool rainy springs in a row and I got nothing but a single plum few years ago. This year was the first real warm hot spring and had a lot of different pollen around also so I think this will most likely be the year. I have some on my tree now that are bigger than big peas and even look like mini plums but I don't expect those all to survive. If the tree doesn't leaf out enough it may not support the fruit and abort like konrad says I think that's what he means,the if it's not ready to support fruit. I have seen trees thin as a twig loaded with fruit and some thicker than 1 litre pop bottles that still won't fruit.

Actually, my dad grafted on, either a different plum tree branch or one from the same tree, and it did grow and produce little fruit. I actually, pruned this branch off the other day. The prune tree is over-shadowing a lemon tree we have and since the lemon tree actually produces fruit we use, I thought it was best to just prune the plum tree back. I still want to prune it back some more, and if possible, somehow get a pollinator companion tree to go along with it. The problem is, there's no space.