Apples

Growing apples is highly rewarding, but don’t try starting one from seed.

Immature apples (Kate Russell)

These particular fruit trees are known as extreme heterozygotes. In plain English, the offspring are nothing like their parents. Planting seeds from a Red Delicious apple will not produce apples that look or taste like that shiny red fruit. It may not taste good at all. Most modern apple trees today are propagated from cuttings grafted onto sturdy rootstock. [Did you know that apples are related to roses?]


Apple history

Apples (Malus pumila, aka Malus domestica) have a rich and varied history. They hold a place in nearly every culture and religion, being one of our earliest attempts at tree cultivation. But wild apple trees (Malus sieversii) bear little resemblance to their domesticated progeny. Wild apple trees, still found in central Asia, can grow 40 feet in height, and the fruit is smaller and more tart than most people find palatable. Most of the apples sold in grocery stores are crosses between Malus pumila and crab apples. There are currently more than 7,500 apple cultivars with various traits of skin color, texture, disease and pest resistance, juiciness, storage ability, and more. In 2010, the entire apple genome was mapped, with over 57,000 genes identified. [Humans are estimated to have up to 25,000 genes. I guess we must be just one big family then.]

Apples come in lots of colors, sizes, and shapes

Bare root apples

The best way to start growing apples is with bare rootstock. Some apple varieties require cross-pollination, while others are self-pollinating. If you only have room for one tree, you need a self-pollinating variety, or all you will get is summer shade. Plant your bare rootstock during late winter or early spring. Before you buy, however, you may want to conduct a soil test with a reputable lab. This inexpensive test is an excellent investment in a tree that will probably live and produce fruit for the next 100 years. Also, consider the size of your mature tree - it is far easier to pick apples and care for your tree if it is a dwarf or semi-dwarf variety.


Chill hours

Chill hours are the accumulated time spent between 32°F and 45°F each year. In this temperature range, the growth-inhibiting hormone responsible for dormancy begins to break down, allowing trees and shrubs to start producing the buds that become the leaves and flowers of spring. The flowers and buds do not form properly unless enough chill hours occur. The number of hours needed is species-specific, so you need to know how many chill hours occur, on average, in your yard before selecting a tree variety.


Red apples generally need 1200 to 1500 chill hours to develop their color and flavor. Green apples need less.


How to grow apples

Apples grow best in well-drained, nutrient-rich soil with full sunlight. Apple trees need some space for good airflow. Full-sized trees will need a 20-foot circle of space, while dwarf varieties need only 10. Dwarf apple trees tend to overproduce, breaking branches, so you may need to do more pruning or provide tree support. You can grow dwarf apple trees in containers.


Once your bare root tree arrives, dig a hole twice the diameter of the spread-out roots and as deep as the root ball. Failing to plant trees at the proper depth is the main cause of tree deaths. Remove any grass or weeds growing within two feet of this circle. 


Remove any dead, damaged, or diseased roots, and then soak the rootstock in a bucket of water for a couple of hours or overnight if they are dried out. Mix some aged compost with soil from the hole and spread it out in the bottom of the hole. Be sure there are no smooth edges in the hole. Heavy clay and other compacted soils can create impenetrable barriers to young roots. You can help your apple tree get a better start by roughing up and scoring the edges of the planting hole. Place the tree in the hole, ensuring that the graft union (where the rootstock joins the scion) is at least 2 inches above soil level to avoid crown rot and other fungal diseases. Resist the urge to tamp down the soil. To eliminate big air pockets, "mud in" your baby tree by watering heavily at planting time.


Seasonal apple tree care

Winter apple tree care includes pruning 15 to 20% of the previous year’s growth, allowing more light to reach the middle of the tree, removing dead or diseased branches, and spraying dormant oil to control San Jose scale, and aphid and mite eggs.


In spring, treat apple trees with a fungicide to help prevent powdery mildew and apple scab. These treatments should occur when the twig tips first green, when the buds are pink, and then every ten days until the rainy season ends. Thin the tiny fruits to one every six inches for better growth and flavor. If apple maggots or codling moths have been a problem in previous years, bagging the fruit or coating it with kaolin clay are organic methods of protecting your valuable crop. Before you start irrigating a mature apple tree in spring, feed it with two pounds of urea or 40 pounds of aged manure.


Summer chores include feeding young trees 20 pounds of aged manure or 8 ounces of urea every month and watering it in. (If you use drip emitters, be sure you do not use more than 1 ounce of urea per emitter per application.) Spray for codling moths from late spring to the end of summer, and monitor for aphids and mites. Irrigate trees every 2 to 3 weeks. As you pick ripe apples, watch for and remove any mummies you come across.

A nice apple harvest

After harvesting, fertilize mature trees the same way you did in summer. Remove all leaves from around the tree and compost them to help prevent apple scab. Mulching around (but not touching) your apple trees will reduce weeds, stabilize temperatures, and provide the slow release of nutrients.


Apple pests and diseases

Few pests or diseases will kill an apple tree outright, but it has many attackers. The use of sticky barriers around the trunk will halt some, such as ants, slugs and snails, and Fuller rose beetles, but most apple problems come in on the wind. Stem blight, crown gall, leaf spot, powdery mildew, fireblight, and other bacterial blights are common diseases of apple trees. Cedar apple rust can also occur if apples are grown near Eastern red cedar trees. Also, apples share a susceptibility to bacteria blast with lilacs and stone fruits. 


Common pests include codling moths, apple maggots, San Jose scale, redhumped caterpillars, armyworms, and Eriophyid mites. New to the apple scene is another pest, chili thrips. Also, any local fog can cause more russeting. Russeting is when the apple skin turns brown and rough.


Find a spot in your landscape for one of these beauties because plucking an apple from your very own tree and taking a bite, well, it's just one of life's finer experiences. And we all want to keep that doctor away!