Growing Fruit in Containers and Pots
Growing Fruits in Pots
The growing of fruit in pots is a very old practice which has come back into favour over recent years. The full range of fruits may be grown including apricots, apples, pears, cherries, plums, peaches,, figs, nectarines, citrus fruits, and so on. No great demand on space is made and are available for other activities at various times of the year. The growing of fruit in pots allows the production of limited quantities of superlative quality fruit in areas which may be so bleak and exposed that outdoor culture is impossible. It is also useful for the production of fruit for the show bench.
Only greenhouses of good design and well situated to receive full sunlight should be considered: a greenhouse partially shaded by a vigorous peach or vine is not really suitable, although if it is a lean-to structure and a peach is grown on the rear wall, pots may certainly be grown in the front portion. Fruit in pots is an interesting and tempting subject for the conservatory that is also used for recreation. It is not generally necessary to think in terms of artificial heat, except perhaps the very minimum in the coldest areas. The pots are placed on the greenhouse floor —, ashes or concrete — and frequently on bricks to prevent supplementary rooting.
Type of bush
A restricted growing habit is essential, which involves the use or training of specially shaped trees grown on dwarfing rootstocks obtained from a reliable nurseryman. The skilled gardener can start with a ‘maiden’ (one year grafted) on a dwarf root stock and shape the tree, but it is generally better to buy specially shaped trees from a nurseryman, and better still if the bushes are already established in pots, three years old, and well furnished with buds so that fruiting can start immediately. With maidens it takes time to build up the framework before fruiting commences.
Delivery of trees is best taken in the autumn at dormancy or leaf fall, when they are potted up into 23cm (9in) pots. It is unwise to put a small bush into a large pot of 25-30cm (10-12in) diameter, as the secret of success with pot-grown trees is root restriction, though as the trees get older 30 cm (10-12in) or even larger pots. The pots used should be very sturdy and have holes in the sides as well as in the base. Only the heaviest gauge plastic pots should be used, it being necessary in some cases to put one inside the other to impart sufficient strength, boring holes in the sides with an electric drill. If new clay pots are used they must be soaked well before use, and all pots must be scrupulously cleaned by washing. All pots are given a deep layer of drainage in the form of broken pots of pebbles over which is put a layer of coarse peat or coarsely shredded peat.
Much is made of the need for a good turf-based compost derived from stacked turf and it is unlikely that this can be bettered by any of the modern composts. Through the loam for apples and pears should be mixed onc-third part of very well rotted farmyard manure or well-made, reliable. For apricots, peaches, nectarines and figs avoid the farmyard manure but add bonemeal and lime at 114g (4oz) and 56g (2oz) per 36 litres/bushel respectively. The compost should be well mixed and under cover for a few weeks before use, finally adding some coarse bone-meal plus a liberal scattering of ground limestone. The compost should be sufficiently moist, rendering it so by watering if necessary.
Shorten all vigorous lateral and downward growing roots before potting up with great care, packing the compost in with a potting stick in layers until it is 2.5cm (1in) below the rim of the pot.
After potting the trees must be well watered and placed in a sheltered situation at the foot of a sunny wall, the pots of `hardy’ trees being plunged to their rims in good soil or ashes or alternatively protected with straw or peat to avoid damage by freezing, care being taken that they are not. Hardy trees — apples, pears, plums and cherries — can remain out of doors until the buds begin to swell; apricots, peaches, nectarines, vines, figs and citrus fruits are better brought into the greenhouse immediately after potting, being given plenty of room and ventilation.
While the culture of fruit in post demands considerable care and attention to detail, it is remarkable what can be achieved by regular watering and feeding; indeed, because of the limited root area the importance of this cannot be over-stressed. It is also essential that free ventilation should be given in the morning and excessively high temperatures avoided, particularly during the initial period of stoning in the case of peaches and nectarines. Assistance with pollination of all trees is desirable, using a rabbit’s tail or cotton wool.
Regular spraying is essential to encourage healthy growth of leaves and to discourage attacks of red spider, which can have a disastrous effect. Feeding with liquid manure should be practised after the fruits are set, once fortnightly at first, increasing the applications to once weekly later. As soon as the trees are in full growth a top dressing of equal parts of well rotted farmyard manure and soil should be given and moulded up round the edge of the pots, raising their height several inches to allow watering. Alternatively rings of linoleum or other suitable material can be used to contain the top-dressing material effectively.
Pruning and fruit thinning
In spring and summer there should be reduction of new growth. With apples and pears lateral growths should be pinched back to about 10-13cm (4-5in) or less, leaving only a proportion of them in the case of apples, otherwise the tree will become a tangled mat of growth. Peaches and nectarines, which fruit on new wood, should have well-placed shoots selected and allowed to make reasonable growth before having the tips pinched out. Some thinning of fruit will be necessary, leaving only one fruit per cluster on apples and pears and thinning plums out singly every 5-8cm (2-3in) or more, while peaches and nectarines should only be allowed to form one fruit per reasonable area of tree to avoid overcrowding. Figs should only have their shoots thinned. Apples and pears can be taken out of doors when the fruit is ripening and the pot plunged in soil for safety and conservation of moisture. Wind damage can be avoided by securing each fruit with raffia to a convenient branch.
After fruiting, all types of trees are ripened off by placing out of doors, carrying out any re-potting in mid autumn. Annual repotting is advisable in many cases, moving vigorous trees to a slightly larger pot. Again, the hardy trees can remain out of doors in a sheltered spot but the rest should be brought into the greenhouse.
Pruning is carried out by reducing the laterals in apples, pears and plums to within two or three buds of the base, and on trees such as peaches, which fruit on new wood, leaving only a proportion of well-placed sturdy shoots to bear the following year’s crop.
Specific pest and disease control is best; there is generally not the same need for the routine practices necessary with bushes out of doors.