Top Fruit and Tree Fruit
Tree fruits are also sometimes referred to as top fruits. In a large garden you can grow fruit trees such as apples (z 4), pears (z 4), plums (z 5) and cherries (z 3) together in a mini-orchard. Where space is limited, train them against walls or fences or along a framework of posts and wires. Alternatively, plant them as specimen trees in a lawn or border; dwarfing rootstocks will keep them small, but make sure pollination requirements are satisfied.
• Growing conditions
Most fruit trees do best in a sunny, sheltered spot. This is particularly the case with dessert varieties because sunshine affects the flavour and colour. Cooking varieties of apples and plums are the most tolerant of some shade. Wind causes fruit to fall, damages growth and deters pollinating insects. Avoid frost pockets as the blossom of most tree fruits is very sensitive to frost. In cold areas, train trees against walls to give them extra warmth and shelter.
A deep well-drained soil is essential, and ideally the pH should be about 6.5 (see Knowing Your Garden Soil). Break up any hard pans and improve poor or heavy soils with compost or leafmould. Correct any mineral deficiencies (see Plant Mineral Deficiencies) and dig in well-rotted manure before planting.
• Clearing the ground
It is not always necessary to clear ground completely before planting. Surround trees with a light-excluding mulch — cardboard or newspaper under hay or straw, for example (see Controlling Weeds).
Dwarfing rootstocks are available for most types of fruit trees. They reduce their vigour and also bring them into cropping earlier. For example, an apple tree on an M27 rootstock has a spread of only 2.5-3m (8-½ – 10ft) and can bear fruit within three years of planting. The size of the tree will also depend on the variety you choose and your soil. For example, an apple variety such as Bramley is very vigorous and can be grown on a more dwarfing rootstock than a weak variety. On poor soils choose less dwarfing rootstocks as trees will naturally have less vigour.
To get good crops, many types of fruit tree must be grown with another variety of the same fruit thatat the same time.
The transfer of pollen can then occur between the two varieties. This cross-pollination is necessary for most apples, pears, sweet cherries, and some plums and gages. It can also improve the cropping of other fruits.
Nursery catalogues should give the “pollination group” of each variety, determined by when it flowers. In general, varieties that are either in the same or adjacent groups will cross-pollinate.
• Choosing varieties
Different varieties of apples, plums and pears can have very different properties and it is important to choose one to suit your site — for example, grow late-flowering or frost-tolerant varieties in areas prone to late frosts. Look for varieties particular to your locality as these are likely to do well, and also those less susceptible to prevalent pests and diseases (see Organic Gardening – Preventing Problems). Specialist nurseries are most likely to have a range of varieties and stock certified as virus-free.
Mulch around young trees to keep at least 1sq m (1sq yd) clear of weeds and grass. Maintain these clear areas around trees on dwarfing rootstocks throughout their life. Hay makes a good mulch as it also feeds the trees. Do not apply it until late spring as its light colour increases the risk of frost damage. Remove any remains of the previous year’s mulch in late autumn, along with fallen leaves and fruit. If the trees need supplementary feeding, mulch with compost in spring. It is important to note that feeding with nitrogen-rich manures or fertilizers can cause growth of leafy shoots at the expense of fruit and increase the risk of some diseases.
Prune apples and pears in winter to remove any diseased or damaged wood and shape the trees (see Pruning Tips and Advice). Trained forms such as cordons and espaliers should be pruned from mid- to late summer to keep them in check and to encourage fruiting. Never prune plums and cherries in winter because this increases the risk of infection by silver leaf disease (see Pests and Diseases of Tree Fruit).
Water regularly in dry spells when fruit is forming, applying up to 22 litres (4-3/4gal) per week to mature trees in mid- to late summer. This helps to avoid fruit splitting, premature leaf fall and disorders.
• Pests and diseases
Many predators of fruit pests become established in and around fruit trees that are not sprayed. Encourage beneficial insects into an orchard by underplanting some areas with attractant plants.
Good hygiene is very important. Remove fallen fruit and leaves if possible, or mow to chop them up and hasten their decay. Pick all mummified fruit off trees to help prevent the carry over of disease to the next year. See see Pests and Diseases of Tree Fruit for details of pests and diseases.