If you're planning to start a home orchard or just want a few apple trees (Malus spp.), it's important to choose the best type of tree -- standard, semi-dwarf or dwarf -- for your garden. A bit of care at planting time and during the first one or two growing seasons also can help ensure a good crop for years to come.
Varieties and Sizes
An apple tree is grafted onto another tree's roots and a lower stem -- called a rootstock -- that determines the size of the mature, joined tree. A full-size tree, called a standard, can be up to 25 feet high and wide; the variety Stark Golden Delicious (Malus 'Mullins') is one example that's available as a standard tree. Semi-dwarf trees, such as the variety 'Braeburn' (Malus 'Braeburn'), can grow about 15 feet tall and wide while dwarf trees, such as the Starkspur Winesap (Malus pumila 'Thornton'), are only 10 feet tall and wide at most. These three examples are hardy in U.S. Department of Agriculture plant hardiness zones 5 through 8.
Some apple varieties are called "self-fruitful" or "self-fertile" because their flowers can self-pollinate; if you have space for only one tree, ensure you choose one of this type. The variety Grimes Golden (Malus domestica) is self-fruitful and hardy in USDA zones 5 through 8. Other trees, including the cultivar 'Honeycrisp' (Malus pumila 'Honeycrisp'), which is hardy in USDA zones 3 through 6, require pollination by a different apple variety, such as a 'Stark Golden Delicious' tree. So at least two apple tree varieties are necessary for them to get an apple crop.
Timing and Site Selection
When planting, space trees according to their mature size. For example, allow about 25 feet between standard trees and 10 feet between dwarf trees. The best time to plant apple trees depends partly on the climate where you live. In USDA zones 6 and higher, you can successfully plant the trees in early spring, before the trees' new leaves appear, or in fall, after the trees have dropped their leaves and become dormant. In colder areas, planting in fall is risky because new growth can be harmed by winter cold. In those regions, start new apple trees in spring for the best results.
Choose a planting site in full sun -- at least six hours of direct sun exposure daily -- for the trees to produce the best flowering and the most fruit. Apple trees grow well in any type of garden soil, provided it's well-drained. If your soil contains clay and drains slowly, then amend the planting area with 2 to 3 inches of coarse sand, mixing it into the soil well with a fork before planting. It also helps to mix about 2 inches of compost into the soil at the same time to boost soil fertility.
Water and Fertilizer
Providing adequate moisture for apple trees is important, especially during their first one or two growing seasons. Water the trees' soil well at planting time, slowly pouring at least 1 to 2 gallons of water onto each tree's base after you've tamped the soil. Watering and tamping also help to ensure no air is trapped around the roots. Give the trees extra water whenever the top 1 or 2 inches of soil feels dry to your fingertip; use a soaker hose or drip irrigation to allow the water to sink slowly into the soil. Those methods also keep foliage dry, helping prevent growth of fungal organisms.
Fertilize apple trees once each year in spring, when their new growth just begins, to help boost that growth and promote heavy fruiting. Use a 10-6-4 granular formula, scattering it on the ground at each tree's drip line -- the area that encircles the tree under its outermost branches. This is where most "feeder roots" that take up water and nutrients are located. For a spring-planted tree, wait until about one month after planting for the first feeding. If you plant in fall, start fertilizing the next spring. Use 1/2 pound for the first feeding, and increase the amount by about 1/2 pound each additional year. For example, use 1 pound for a 2-year-old tree and 2 pounds for a 4-year-old tree. For a tree aged 15 years or older, use 7 1/2 pounds of fertilizer.
A newly planted apple tree benefits from a supporting stake that prevents it from swaying in wind, which can interfere with new root growth.
Drive about 2 feet of a 2-inch-square wooden stake vertically into the ground beside each apple tree at planting time. The stake should be 10 feet tall for a dwarf tree and remain in place for the tree's life. For a semi-dwarf or standard tree, use a 6- to 8-foot-tall stake, and remove it after about five years.
Cut sections of strong wire for each tree. Each wire section needs to be long enough to pass around its respective tree's trunk and back to the tree's stake with several inches to spare.
Run one apple tree's wire through a piece of garden hose or rubber tubing, and place that material at the wire's midsection. Rest the hose or tubing against the tree. The material will protect the tree from the wire's abrasion. Pass the wire's ends around the tree's stake, and twist the ends together securely. Repeat the procedure for each apple tree.
Control weeds near the trees because weeds compete for moisture and nutrients. Using 3 to 4 inches of organic mulch on the soil surface under each tree will help to suppress weeds and conserve soil moisture, but keep the mulch several inches from every tree's trunk to prevent fungal growth. Clearing leaves and other plant debris from under the trees on a regular basis also helps prevent fungal problems.