The plum tree I planted did not make it and my lemon tree is suffering.
What are some good methods for planting and caring for fruit trees?
Our soil tends to be a mix of heavy clay & rocks.
When I plant a new tree, I dig a BIG hole - about 2x the size I think the tree needs, so it has good dirt for at least the first year or two. I mix the clay soil with one part soil: 1 part well rotted horsemanure (3-5 years old, from a Rubbermaid garbage can I fill from time to time at the stables where we used to board), witha couple of trowels full of dry coffee grounds (kept in Gatorade & juice bottles after they dry, stored in the shed), & a couple of scoops off TerraSorb ( a landscape aid that helps hold water - good in the desert). I usethat mixture to plant the tree. the "leftover" clay soil from digging the hole gets sprinkled on the garden, on top of the lasagna layers of mulch, where it gets incorporated without causing issues.
Do NOT plant the tree lower than it was planted in the pot. It will die if you do. Ditto for planting a fruit tree in a low spot in the yard. Learned that one the hard way. If you have animals across a fence, be sure they cannot reach the tree. They will eat it if they can. Learned that one the hard way, too. Choose a location where the tree will be in good sun for most of the day. Keep in mind it will grow, so don't put it too close to the house, sidewalk or driveway, or you will regret it later.
I mulch a couple of inches deep on top with grass clippings (we use no chemicals on our grass), to keep it from drying out, but keep the mulch a couple of inches from the trunk. I water the trees with the grass, because that is where they are planted, but in the fall & spring, I make sure they each have a deep, long drink, usually the night before it is forecast to freeze.
In January or Feb here, I spray the trees with a dormant oil spray. I choose not to use the kind with chemicals. My dad used to go out & use an old paintbrush to paint vegetable oil on the trunks & main stems of the apple trees in the orchard - we had about 10-12 trees back there. He found it relaxing, & frankly, since my trees are small, it is easier to paint them than to get oil in my face from the wind & the sprayer when it is cold outside, & I believe I miss less spots that way. The oil dissolves the protective coatings around the insect eggs, which are laid on the main trunk of the tree & they are killed by the cold. My plums tend to have more trouble with aphids & other insects than the apples, cherries, pears or apricots do. Might just be where I live, but it was that way when we lived in Idaho, too.
For the 2nd year, I usually pull back the mulch & add a thin layer of the manure, then replace the mulch. If the tree looks like it is struggling ( some areas of our yard have harder clay than others), then I foliar feed it with the watering can & some fertilizer than can be dissolved in water, then sprayed on the plants. It helped the walnut tree for the 2nd -5th years to get strong enough roots to punch through the clay to the water table beneath it. That tree is doing fine now.
When the trunk is over 1 1/2 inches, you can start using the "spike" type fertilizer for fruit trees bought at the ranch supply stores. You put a plastic cap on top of the stake & pound it into the gound under the tree's dripline. Works better if you pound in a stake first, since the fertilizer spikes tend to break, but it isn't hard & makes a big difference in how fast the trees grow & how soon they fruit.
Learn how to prune the tree. Cherries, peaches & other stone fruits are usually pruned into a vase shape. Apples & pears have a central leader. Google pruning & you will see examples. It is not hard to do. You can buy little plastic "limb spreaders" that help form the proper angles for the developing branches, or you can use branches you have pruned off to whittle your own.
Int he spring, when you notice fruit, you will need to thin the fruit, or your plums will be mostly seed with not much plum. I reduce each cluster to one, but I do not thing until after the start of summer here, because we get strong winds that thin a lot of the fruit for me. Be careful when you pick the fruit, with for thining or harvesting, not to damage the fruit "spur" - the tiny twig-type projection from which the stem comes. The spurs will bear the fruit multiple times, so if you rip it off, the tree will not be able to set as much fruit.