Fruit trees bear at different times of the year. For example, there are apples for early season, midseason, and late-season (well into fall), so it is wise to select trees for the season you want. Just how long it will be before trees will bear is another consideration; apples and pears bear in 4 to 6 years; plums, cherries, and peaches bear in about 4 years.
Besides considering bearing season and length of bearing, you should also think of size. In addition to standard-sized fruit trees there are dwarf varieties that grow only a few feet. There are also different kinds of apples, peaches, or cherries; your local nursery will tell you about these. Your nursery also stocks the type of trees that do best in your area, so ask for advice. Your trees must be hardy enough to stand the coldest winter and the hottest summer in your vicinity.
Many varieties of fruit trees are self-sterile, which means that they will not set a crop unless other blossoming trees are nearby to furnish pollen. Some fruit trees are self-pollinating or fruiting and need no other tree. When you buy your fruit trees, ask about this. Fruit trees are beautiful just as decoration, but you also want fruits to eat.
Buy from local nurseries if possible, and look for 1- or 2-year old trees. Stone fruits are usually 1 year old and apples and pears are generally about 2 years old at purchase time. Select stocky and branching trees rather than spindly and compact ones because espaliering requires a well-balanced tree.
Whether you buy from a local nursery or from a mail-order source (and this is fine too), try to get the trees into the ground as quickly as possible. Leaving a young fruit tree lying around in hot sun can kill it. If for some reason you must delay the planting time, heel in the tree. This is temporary planting: dig a shallow trench wide enough to receive the roots, set the plants on their sides, cover the roots with soil, and water them. Try to keep new trees out of blazing sun and high winds.
Prepare the ground for the fruit trees with great care. Do not just dig a hole and put the tree in. Fruit trees do require some extra attention to get them going. Work the soil a few weeks before planting. Turn it over and poke it. You want a friable workable soil with air in it, a porous soil. Dry sandy soil and hard clay soil simply will not do for fruit trees, so add organic matter to existing soil. This organic matter can be compost (bought in tidy sacks) or other humus.
Plant trees about 10 to 15 feet apart in fall or spring when the land is warm. Then hope for good spring showers and sun to get the plants going. Dig deep holes for new fruit trees, deep enough to let you set the plant in place as deep as it stood in the nursery. (Make sure you are planting trees in areas that get sun.) Make the diameter of the hole wide enough to hold the roots without crowding. When you dig the hole, put the surface soil to one side and the subsoil on the other so that the richer top soil can be put back directly on the roots when you fill in the hole. Pack the soil in place firmly but not tightly. Water plants thoroughly but do not feed. Instead, give the tree an application of vitamin B12 (available at nurseries) to help it recover from transplanting.
Place the trunk of the fruit tree about 12 to 18 inches from the base of the trellis; you need some soil space between the tree and the wood. Trellises may be against a fence or dividers or on a wall. Young trees need just a sparse pruning. Tie branches to the trellis with tie-ons or nylon string, not too tightly but firmly enough to keep the branch flat against the wood. As the tree grows, do more trimming and tying to establish the espalier pattern you want.
To attach the trellis to a wall use wire or some of the many gadgets available at nurseries specifically for this purpose. For a masonry wall, rawl plugs may be placed in the mortared joints, and screw eyes inserted. You will need a carbide drill to make holes in masonry.
Caring for fruit trees is not difficult. Like all plants, fruit trees need a good soil (already prepared), water, sun, and some protection against insects. When trees are actively growing, start feeding with fruit tree fertilizer (available at nurseries). Use a weak solution; it is always best to give too little rather than too much because excess fertilizer can harm trees.
Observe trees frequently when they are first in the ground because this is the time when trouble, if it starts, will start. If you see leaves that are yellow or wilted, something is awry. Yellow leaves indicate that the soil may not contain enough nutrients. The soil could lack iron, so add some iron chelate to it. Wilted leaves could mean that water is not reaching the roots or insects are at work.