Apple tree

Light and exposure

The apple tree wants sun to ripen its fruit and concentrate the sugar. Give it an open, sunny spot with at least six hours of direct light a day. In a shady garden the tree still grows, but the harvest stays meagre and the fruit tastes bland.

An airy position where the air circulates well is worth its weight in gold under a damp climate: the foliage dries faster after rain and scab settles in less easily. Avoid valley bottoms where cold air pools and where spring frosts linger longer during flowering.

Watering

An apple tree well rooted in open ground manages on its own most years, since ordinary rainfall covers its needs. During the first two or three years after planting, however, water generously in case of summer drought so the root system establishes itself deeply.

Keep a special eye on young trees and espaliered forms on dwarfing rootstock, whose roots stay shallow and quickly suffer from dryness. A mulch at the base keeps the soil cool and saves you from watering all the time. In a hot, dry summer, a lack of water while the fruit is swelling means smaller apples.

Soil and repotting

The apple tree accepts most soils, but prefers a deep, cool, well-drained earth, neither too chalky nor permanently waterlogged. Heavy clay soils suit it fine, as long as water does not sit around the roots in winter.

At planting, dig a wide hole, loosen the bottom and work in mature compost without burying the graft point, which must stay well above the soil. Ground that is too soggy encourages root rot and root suffocation: on wet land, plant on a small mound to raise the collar.

Temperature and humidity

The apple tree is perfectly hardy in temperate climates: in dormancy, ordinary varieties take -25 to -30 °C and the hardiest down to -35 °C, that is USDA zones 3 to 8 depending on the cultivar. It actually needs a certain number of chill hours each winter, 800 to 1200 hours below 7 °C for most varieties, to break the dormancy of its buds and flower properly; under too mild a winter, only low-chill varieties give anything.

The sensitive point is flowering. The apple tree flowers fairly late, about a week after the pear, which partly protects it from the last frosts. But a night at -2 °C during full bloom scorches the flowers and ruins the year’s harvest. In cold hollows, a late frost at that moment makes all the difference between a fine year and a blank season.

Pruning and upkeep

Formative pruning is done in the first years, in winter and out of frost, to build a balanced, airy framework. You open the centre of the tree to the light and keep well-spaced branches. On a standard orchard tree you let it spread; on an espalier or goblet form you guide each branch.

Maintenance pruning, also in winter, removes dead wood, crossing branches and surplus watershoots, while renewing the fruiting spurs. Summer pruning is possible: you pinch or shorten the year’s growth, which calms vigour, lets sun onto the fruit and encourages fruit buds for next year. There is no point pruning an over-vigorous tree hard, it simply responds by growing back stronger.

Pests and diseases

The number one enemy under a damp climate is scab, a fungus that covers the leaves with olive-brown spots and marks the fruit with black corky scabs. It explodes during rainy springs, when the foliage stays wet for a long time. The best defence is to choose resistant varieties from the start, often old local varieties suited to the orchards of your own region, and to rake up and remove the fallen leaves in autumn, where the fungus overwinters.

Codling moth, the famous apple worm, tunnels through the fruit: pheromone traps and trap bands around the trunk help to keep it in check. Watch out too for aphids, which curl up the young shoots in spring, and powdery mildew, that white felting on young leaves and shoots in mild weather. Cut and burn affected shoots, and encourage helpers like ladybirds rather than spraying at random.

Propagation

The apple tree does not come true from seed: a pip gives an unknown tree, rarely good to eat. To get a specific variety, you propagate it by grafting onto a chosen rootstock. It is the rootstock that decides the final size: a dwarfing rootstock gives a small tree for a little garden or an espalier, a seedling stock gives a vigorous standard for a full orchard.

Grafting is done by budding at the end of summer, or by cleft and whip-and-tongue in spring on a rootstock planted the previous winter. It is a technical but accessible gesture, very rewarding when you want to save an old local variety. For the gardener in a hurry, buying a grafted maiden from a nursery is the simplest route: you then choose the variety and the rootstock in one go.

Month-by-month care calendar

Green Hub tips

• Always plant at least two compatible varieties that flower at the same time, or check that an apple tree already grows at a close neighbour’s: without cross-pollination, many varieties give little or no fruit.
• Choose the rootstock according to the space: dwarfing for a small garden or an espalier against a wall, seedling stock for a full-orchard standard that will live for decades.
• Under a damp climate, bet on old local varieties resistant to scab, far easier to grow than supermarket varieties.
• Rake up and remove the dead leaves in autumn: that is where scab overwinters, and a clean base breaks the cycle for the following year.
• Do not pick a keeping apple too early: it should come away easily with a light twist of the hand, otherwise it will shrivel in the cellar.