How to Grow The Morello Cherry
The Morello cherry is distinct from the sweet cherry. It stems from a different species, Primus cerasus, which accounts for the difference in stature, habit and flavour. Hybrids between the acid and sweet cherries have given rise to a group known as ‘Dukes’. The term Acid or Sour is used to denote the group as a whole. ‘Morello’ is the one most suitable for gardens. Soils, sites and forms
The Morello will prosper on soils not ideal for sweet cherries and will put up with the shade of north-facing walls, if need be. It lends itself to wall-training much more readily than does the sweet cherry, but it would be a pity to use any but a north wall for the growing of Morello cherries, since they can be grown so easily as bushes on a short leg.
Rootstocks and spacing
The Morello, so unlike its sweet cousin, actually needs stimulating and needs a vigorous rootstock to keep it going. The clonal selection already mentioned, Mailing F 12/1, is the one most widely used.
Both wall trees, trained as fans, and bush trees should be spaced at around 5m (16ft) apart, less on the thinner soils. One-year-old trees are particularly suitable and grow away quickly, with the aid of the usual careful planting, staking and mulching. The head of the bush tree should be formed by the shortening of the maiden tree to about 60cm (2ft) to encourage the production of primary branches in the same way as for apples. Once the head has been formed pruning consists merely of the removal of crossing branches and the deliberate cutting back into old wood of, say, three branches each year. This is necessary to ensure that the bush is kept in a compact and fruitful condition. Without this branch shortening the Morello cherry tends to carry most of its fruit on the outer skirts of the tree. Leave the selective branch cutting until May, so that the cut can be made to a newly started shoot.
Since they have to carry both a heavy crop and produce the bearing wood for next year at one and the same time, the generous manuring programme suggested for pears is exactly right for Morello cherries. For the same reasons, keep downbecause competition for moisture and nutrients slows down growth considerably. Irrigation during dry spells is a great help, but not once the fruit starts colouring.
Varieties, pollination and harvesting
This could not be easier, because the Morello cherry, the only one recommended, sets fruit with its own pollen. All that is required is a frost-free flowering period and plenty of bees.
The fruits should be left until ripe, birds and splitting permitting, and then removed by snipping the stalks with a pair of thin-bladed scissors. They can, of course, simply be pulled off in the old-fashioned way but this tends to tear the bark and to let in the nasty fungus disease which causes brown-rot.
Pests and diseases
The main troubles are blackfly, birds, brown-rot and silver leaf. Blackfly should be prevented by the pre-blossom spray recommended for sweet cherries. Birds can be to some extent deterred by glittering strips of foil or plastic and similar scaring devices, or even by netting, which becomes practicable, but messy, with this small tree.
The keen fruit grower, asked what he wants for Christmas, should ask hopefully for a permanent fruit cage.
Brown-rot and silver-leaf are not controlled by spraying, but much can be done by straightforward hygiene, removing rotting fruits and silvered branches when seen. Uses
Peaches and nectarines in the garden
The word Nectarine, like Fragaria, is one to cherish. In truth it is not a generic name and denotes only a peach with a smooth skin. Claims have been made that the flavour of nectarines is superior to that of peaches with fuzzy skins, but the evidence for such a sweeping assessment is not strong.
Peaches and nectarines can be regarded for all practical purposes as requiring the same treatment. Background
Most peaches on sale in the shops are imported, but the peach can be grown successfully in the open in Britain, although the weight of crop tends to fluctuate in relation to the type of weather prevailing at the time of flowering.
The peach is botanically Primus persica, but its origin is from China rather than Persia. When grown in this country it foolishly persists in flowering early, often before the leaves appear. The bleak winds and chilling frosts of early spring then take an inevitable toll. Point number one then: peaches grow superbly well in glasshouses, perform satisfactorily when grown on walls, and tend to behave erratically in the wide open spaces.
The moral is the obvious one, the peach should be given a favourable site for good results.
Despite the rather discouraging tone of the opening notes the gardener in the south of England at least should not hesitate to try his hand at peach growing, if he has room.
Windswept sites and obvious frost pockets should be avoided, but shade and competition from nearby trees is equally to be eschewed, no matter how sheltering their embrace.
The soil should be deep, well-drained, yet retentive of summer moisture, a tiresome repetition, but a necessary one because the peach, like the blackcurrant, has the dual task of carrying a crop and replacing the bearing shoots in the same year.
There is still a feeling around that a stone fruit, such as the peach, must have plenty of lime to prosper. It may be a confused linking of calcium and bones which gives rise to this erroneous notion. Those travellers who have seen peach orchards in the limestone areas of Italy will readily appreciate that too much lime locks up iron and manganese in the soil, giving rise to bright yellow rather than green leaves. A soil pH level of around 6.2 is about right. In other words, only markedly acid soils need liming.
One returns to the thought of a south-facing wall as the ideal, knowing that few-can follow such advice, or even the less desirable alternatives of west or east facing walls. But some can, and they should.
Paradoxically the more cosy conditions tend to bring about still earlier flowering, and it is wise to equip the peach wall with means of providing quick and temporary protection on frosty nights during the susceptible period. Light hessian, plastic net-ting and similar materials will provide enough retention of heat to prevent severe damage. The protection should not actually touch the tree and must be removed during the daytime, unless an unusual wind frost occurs during the daylight hours of spring.
Apart from the risk of frost damage to the delicate flowers and fruitlets the peach is perfectly hardy and needs no winter protection, always allowing for the possibility that a new Ice Age cometh, when we will all need protection.
Rootstocks and varieties
One of the charms of horticulture is the constant exception to the rules.
There are hundreds of peach trees in gardens which have been raised from stones sown by green-fingered gardeners, usually women. All these are brand new varieties, growing on their own roots. In the nature of things very few of these speculativeare improvements on existing tried and named varieties, but many are sufficiently good to warrant a continued life, nourished by their proud foster-parents.
Peach seedlings are used in some parts of the world to provide rootstocks for the cultivated varieties, but performance is apt to be variable and it is best for the amateur to buy his trees on predictable clonal rootstocks. The best, at present, for the amateur is the plum rootstock St Julien A, which produces a small, early bearing, compact tree.
Varieties are numerous and the choice confusing:
Rochester. An American variety, outstanding on open ground. If only one tree can be grown, this is it.
Hale’s Early. Rather less robust, but of better quality; a yellow fleshed variety which ripens in late July and is said to freeze well. The even better Peregrine, an August variety, is worth trying even in the open. On walls the choice is wider, including the three varieties already mentioned and the later ripening Bellegarde. Early Rivers and Elruge are two nectarines with good records.
All but one of the varieties mentioned are, so far as is known, self fertile and can be planted on their own. The exception is Hale’s Early, which demands a compatible mate. The real problem is not cross-pollination, but the distribution of the pollen within the flowers. This is normally achieved by insects, but there are not many about when the peach is in flower and the grower of peaches should not hesitate to encourage the spread of pollen by using a tuft of cotton wool as suggested in the page on the growing of peaches and strawberries under glass.
For good results the recommendations made in the earlier reference to the planting of apple trees should be followed carefully. A good start is all important.
Trees on walls on St Julien A should be spaced at 5m (16ft) apart. In the open ground bush trees require the same sort of space, in all directions.
Pruning and training
Trees on walls are usually trained in a fan shape, this being the most efficient way in which to occupy the space. Building up a fan is a fascinating but lengthy process, and many gardeners will prefer to buy a tree in which the initial framework has been formed by the expert nurseryman.
It is best to buy such a tree direct from a specialist rather than a local garden centre which, understandably, obtains from elsewhere the plants for which there is a limited demand.
The dedicated gardener, wishing to train his own fan tree, will buy an unpruned maiden tree and follow the recommendations contained in the sections on pruning. Similarly the training of an open-centre bush tree to stand in the open garden follows exactly the same principles laid down for the shaping of a bush apple tree.
The pruning of the fan tree in the fruiting stage is quite different from any other fruit yet discussed. The basic principles to adopt are, however, quite straightforward—any very strong shoots growing outwards from the wall, any shoots misguided enough to grow inwards towards the wall, any cankered or broken shoots or branches—all these are removed completely at the end of the growing season.
This leaves for attention the fine tracery of twigs and shoots radiating from the arms of the fan, all neatly tied in to the wire framework.
The peach fruits best on shoots of the previous year’s growth. Each shoot carries a mixture of buds: pointed wood buds, rounder blossom buds, and compound units consisting of two fruit buds and one wood bud. The aim is to encourage the production of these shoots in the right places. Once the fruit has been picked the shoot can and should be cut out and a new one tied in its place.
This really is all you need to know, but you can go further and increase the strength of the selected new shoots by removing or pinching-back superfluous ones by the technique of de-shooting. It is easy to describe what is involved in this simple operation. Essentially only three growing points are left on each fruiting lateral, a) the one at the end, b) one at the base chosen to replace the lateral, and c) one a little higher up. The last is not really necessary but is left as a belt-and-braces precaution in case disaster befalls the chosen one (and as an added source of sustenance). Either remove all other shoots by finger and thumb, or pinch them back to two leaves if there is a fruit at the joint. Sometimes secondary shoots arise. Pinch these back in turn to one leaf. Similarly the growing point of the extension growth (a) can be stopped at five leaves, if time permits, and if no further extension is needed.
At the end of the season prune out with secateurs the laterals which have carried the fruits. Tie in the replacement shoot.
Bush trees have more space in which to operate and do not receive the same detailed attention, apart from the basic operations earlier laid down with regard to overcrowded, crossing, damaged and diseased branches.
Bush peach trees, like Morello cherries, tend to become bare in the centre and fruitful only on the periphery, and each spring should see a deliberate cutting back of say three branches to new shoots.
The pruner should aim at filling all the space with young cropping wood. What could be simpler? The timing of the pruning is a bit tricky. Prune wall trees in the autumn, after the fruit has been picked. The de-shooting is of course carried out continuously during the summer as the need arises. Bush trees can also be pruned in the autumn, but the shortening of the leggy branches is best left to spring, when the new breaks can be seen more readily.
Prepare the soil well before planting, by thorough digging and the incorporation of any available bulky. Thereafter an annual mulching may suffice for some years, because it is important not to encourage excessive vigour. On the other hand, if the growth of replacement shoots slows down then a dressing in early spring of a compound fertilizer at 100g per m2 (3oz per sq yd) is obviously called for.
Trees on walls, and young bush trees, may suffer from lack of water. The thick annual mulch which forms our routine and pious recommendation helps enormously to retain moisture, but wall trees in particular will in most years respond to frequent waterings from mid-May to mid-September, give or take a cloud burst or two, but not during the ripening period because of the risk of fruit splitting.
In some years there are too many fruitlets. If all were left the result would be fruits consisting largely of stone, an end clearly to be avoided. Nature plays her part in divesting the tree of the unwanted young, and additional thinning should not be done until the stone is well formed and the fruit likely to stick, if permitted. Even then it is best to play safe by a gradual, staged thinning, beginning in mid-June, when all badly placed fruits—those wedged between shoots, for example—and those marked by abortive caterpillar bites are taken off.
Finally each fruit should stand about 20cm (8in) from its neighbour. In some years no thinning is necessary and indeed there may appear to be no crop, but generally there will be enough.
Peaches ripen at intervals over a period of about six weeks. They should be lifted if possible in the palm of the hand, as opposed to being gripped with the tips of the fingers, given a slight twist, and handled afterwards with appropriate tenderness.
Pests and diseases
The worst trouble is the fungus disease called peach leaf curl, readily recognized by the reddening, curling, crimping and blistering of the leaves. It is not easy to control, but every attempt should be made to stop this crippling disease from getting a hold. New research work suggests the possibility of a spray being developed which will kill the over-wintering fungal mycelium, and stop the disease in its tracks. Meanwhile, at least one spray with a copper or lime sulphur fungicide in early February is necessary. If the tree has been badly attacked the previous summer then a spray should be applied in late autumn, followed by two sprays in spring, one in early February and the other a fortnight later.
A spray with malathion immediately flowering is finished will help to control aphids. The same material is useful during the summer to reduce the undesirable effects of the glasshouse red spider mite, which flourishes on wall trees in warm summers and causes the familiar bronzing of the leaves and premature defoliation.