Malus domestica
Family: Rosaceae

Apples are the most widely cultivated fruit of temperate regions. They are also very ornamental trees for the garden, being lovely in blossom, providing shade in summer, bearing delicious, decorative fruit and changing to delightful colours in autumn.

Apples have been cultivated for at least 3000 years, having been bred and improved from wild crab apples. The earliest domesticated apples were probably introduced to Britain by the Romans who were skilled in grafting and pruning and able to produce superior fruit. The wild crab apples had their origins in Europe and Asia.

Over the centuries, a huge range of seedlings were raised, and the best were selected and propagated but generally not recorded. From about the 17th century, varieties were given names which identified the particular fruit with certainty. As America, Australia and New Zealand were settled, new seedlings were raised and the best of these were returned to Britain.

There are today over 2000 varieties of apple grown in the Apple Collection of the Brogdale Horticultural Trust in Kent, England, not far from the East Mailing Research Station where research on apple rootstocks has led to the widespread use of dwarfing root-stocks all over the world. Apples were popular before refrigeration as they stored well. They were often the only fruit available in winter. They are valued as fresh fruit, and for desserts and jellies, cider-making and unfermented fruit juice.

Varieties

It is important to choose cultivars of apple that are suited to your Climate. Bear in mind that apples need cool to cold winters so that they can become dormant. Therefore in regions with mild winters they do not take a proper rest as they are not subjected to sufficient winter cold, and consequently they do not per-form well. It is best to consult your local nursery or specialist fruit grower for advice on the best cultivars for your area.

Among good apple cultivars, 'Delicious', which came to prominence in 1893 as a prize-winning, high quality red apple, is now the world's most widely cultivated apple, especially in warmer regions. It can be cross-pollinated by several varieties including 'Golden Delicious', 'Spartan' and 'Granny Smith'. 'Golden Delicious', a heavy cropper, was introduced in 1916; 'Granny Smith', grown in all the warmer fruit-growing regions, was a chance seedling that first fruited in 1868 in Ryde, New South Wales, Australia, and is used for pollinating many varieties. 'Cox's Orange Pippin', raised in the United Kingdom in 1825, has a rich, sweet flavor. It is the main apple variety grown in England, although it went out of favor for many years because of disease problems.

'McIntosh' was first selected in Canada in 1811 and has been distributed from the 1870s onwards. 'McIntosh' has numerous cultivars and is a very popular variety for cool to cold regions. 'Gravenstein', which is claimed to have arisen as a seedling in Europe in the 1600s, is widely grown in the US and particularly good for California's north coast. Some good modern dessert cultivars include 'Idared', an apple which is very suited to storage; 'Suntan', another late cultivar, which resembles 'Cox's Orange Pippin'; and the early-maturing 'Discovery' with fairly frost-tolerant blossom and crisp, sweet fruits.

Cultivation

Apples for the home garden are usually propagated by budding or grafting on to dwarfing rootstocks such as 'Northern Spy', 'MM 106' and 'M 9'. The 'M' numbers have their origins in East Mailing. Without the research conducted there, seedling apples and many varieties would otherwise be too large both for the home garden and the commercial grower who needs trees of manageable size.

Apples require cross-pollination for reliable cropping so more than one variety should be planted. Crab apples will often cross-pollinate edible apple varieties too. Plant trees less than 10 m (33 ft) apart to ensure adequate pollination. Trees on 'Northern Spy' or 'MM 106' should be planted only 3-4 m (10-13 ft) apart and those on 'M 9' only 2 m (6 ft) apart.

Plant labels should give information on the rootstock used. Shelter from strong wind helps provide protection for pollinating insects, as well as protecting the blossom from premature shed-ding and the developing fruits from damage. Trees should be planted in deep, well-drained soil, enriched with manure or compost. Avoid low ground which may be a frost pocket or susceptible to late spring frosts which could ruin the blossom and therefore fruit set.

Bare-rooted trees should be planted in late autumn or winter, while container-grown trees can he planted out at any time of year. Water trees in well after planting if the soil is dry but do not apply fertilizer at this time. The first fertilizer should be applied in spring following planting. Mulching with well-decayed compost or manure is beneficial at any time. Give trees deep regular watering through the flowering and fruit setting period.

Pruning and Training

Training and pruning is done in summer and winter and there may be a good deal of this to do in the early years. Older trees may need the removal of some of the oldest wood each year to make way for younger, more fruitful growth. The main pruning season for apples is winter. Most fruits are formed on wood that is two years old or older.

Fruit buds are the very plump, round buds rather than the more slender leaf buds. Young trees, however, may have terminal buds on short shoots. Formerly apples were pruned in a vase shape, but nowadays the central leader system, which produces a pyramidal-shaped tree, is preferred, as this results in a tree with a strong structure and encourages early fruiting. In the long term, there is actually less pruning, though a good deal must be done in the formative years.

Trees that are multi-budded, which means they have several varieties on the one stock, must still be vase pruned. The aim of central leader pruning is to develop a tree with three or four layers of branches growing from the central stem or trunk outwards and upwards at an angle of about 30-40 degrees from horizontal. Ideally there should be about four branches in each layer, with a space of about 50 cm (20 in) between layers. This is a simple method of training and pruning. If in doubt, consult a specialist fruit-growing nursery, publications from your Department of Agriculture, or books or brochures written by experts in your area.

Apples should begin cropping by their third season and should continue producing good fruit for about 40 years, and often considerably longer in cool to cold Climates. Hand-thinning when the fruit is about marble to cherry size helps in producing regular, reliable crops. Apples should not be harvested all at once as they ripen over several weeks. Fruit picked too early will taste poor and shrivel; fruit picked when too mature will keep poorly. Fully mature fruit can be picked with a slight lift and twist, and should come away from the tree with the stalk intact.

Pests and Diseases

Unfortunately, apples are susceptible to attack from a number of insect pests and diseases. Scab and mildew are the two most common diseases, while a condition known as bitter pit is common in some types and during some seasons. Insect pests include apple maggot, the codling moth, fruit fly, woolly apple aphid, scale insects, mites and various moths. Semi-dwarfing rootstocks have some resistance to woolly aphid. In many regions much time and effort is put into the control of these pests and diseases.

Climate

Apples grow best in areas with mild summers and cool to cold winters. If the winters are too mild, there will be less blossom and the fruiting will be poor. If the summers are too hot, the fruit may he burnt by the sun and the quality will suffer. Apples are happiest in zones 6 to 8.