Plums, Cherries & Pears
Tree Fruit: Plums and Cherries
Plums and Cherries: Site and soil
Plums and cherries are closely related, have similar requirements and similar problems. Both kinds flower early; plums a little early before cherries. This means that they must have a warm site. Do not plant where cold winds might damage the blossoms, or where cold, frosty air might collect. Plums and sour cherries can be grown on a west, south or north-facing wall.
Both plums and cherries like fairly heavy, limy soil, but it must be well drained. Acid soils should have lime applied before planting these fruits. Remove all weeds from the planting site and dig over an area of about one square metre before digging out a hole and planting to the level of the soil mark on the stem.
Plums and Cherries: varieties
The best and most reliable plum variety is 'Victoria'. 'Opal' is a reasonably reliable variety too. 'Czar' is a small black plum, and 'Denniston's Superb' is a greenish-yellow gage of good flavour. All of these are self-fertile, needing no pollinator. 'Victoria' and 'Czar' can be grown as free-standing trees or as fans on a south, west or north wall. 'Denniston's Superb' is best grown on a south or west wall. Plum varieties are grafted onto 'Pixy', a dwarfing variety.
The best sour cherry variety is 'Morello' which can be grown as a tree or a wall-trained fan. The only variety of sweet cherry suitable for gardens is 'Stella' a recent introduction. Other sweet cherries are too large, and need pollinators. Both 'Morello' and 'Stella' can be grown on their own, usually grafted on the 'Colt' rootstock, which is quite vigorous.
Plums and Cherries: training and pruning
Plums and cherries can be grown as trees or wall-trained fans. Of the restricted shapes only the radiating fan shape is suitable for the growth habit of plums and cherries. Train wall trees into a fan shape by tying in the young shoots as they grow and pruning out badly-placed shoots.
'Victoria' is too vigorous as a wall tree, unless there is a lot of space available. Train plums and cherries as free-standing trees by shortening the young shoots by about one-third of the length, each April for the first few years, letting the trees take their own shape.
Plums or cherries must not be pruned in winter because there is a good chance of diseases getting in through the wounds. Prune plums in spring in the early years and , once established, prune after fruiting. Plums fruit on wood of all ages, and so, some thinning, and the removal of dead, damaged and diseased wood is all that is necessary.
Sour cherries fruit on the previous year's wood so, each year, some old shoots should be removed in late spring, to encourage new growth. Sweet cherries fruit on spurs on old wood. Little or no pruning of free-standing trees is necessary. Wall trees should have new shoots shortened to 10 centimetres in July, once the branch framework is established.
Plums and Cherries: feeding
If the trees are growing vigorously and failing to crop, they need no feeding for a year or two. After the fist two years, give 30 grams of sulphate of potash per square metre in March. If the trees have cropped heavily or growth is not good, give 70 grams of general fertiliser per square metre. Well rotted compost or manure could be used on poorly growing trees too. On very acid soils, apply some lime every three or four years.
Plums and Cherries: thinning and picking
Plum trees, especially 'Victoria', often set too many fruits - even to the point of breaking branches. If too much fruit is allowed to develop, it tends to be small and of poor quality. Thin out plums to about 5 centimetres apart in late June. Wait until the natural fall is complete. No thinning is needed for cherries.
Pick plums and cherries ripe off the tree and use them within a few days, they keep for only a short time. Remove all the fruit from plum trees, because the old, withered fruit can be a source of disease the following year.
Plums and Cherries: weeds, pests and diseases
Use Weedol or Roundup to kill off weeds under plums and cherries. Hoeing, or Simazine, may damage the surface roots. Established plum trees and sweet cherries grow happily in grass.
Greenflies usually attack plums and blackfly attacks cherries, each year. Keep a close watch and spray if numbers begin to build up. Plum sawfly grubs bore into the fruit making them fall early. Treatment is to destroy the early ripening, affected fruits and destroy fallen fruits. Spraying with a contact with Malathion or similar can be carried out in June and early July.
Bullfinches often strip out the flower buds on plums and cherries in rural areas. The crop can be badly affected. Netting may be necessary. Blackbirds and starlings may attack ripe cherries. Netting can be considered.
Silver leaf causes a silvering of the leaves, and a dark stain in the wood of the affected twigs. If the stain is not present, feeding usually restores the tree. If it is present, remove the affected branches completely as soon as they are noticed, as the disease is a killer.
Bacterial canker affects the trunk and main branches, causing off-colour, shothole of the leaves, wilting and death of the tree, often during winter. Copious amounts of gum usually oozes from an infected tree. There is no cure. Both silver leaf and bacterial canker attack through wounds and pruning cuts. Do not prune in winter. Apply Liquid Copper, Dithane or Bordeaux Mixture at leaf-fall as a precaution - especially in wet localities.
Brown rot attacks plums and, occasionally, cherries. The fruit turns brown, with creamy white spots. Do not leave any old fruit on the trees over winter as it will be a source of infection the following year.
Tree Fruit:
Pears: site and soil
Pears need a good site to succeed. They flower earlier than apples and so they are more vulnerable to frost. Fruit quality, too, is better in a warm situation. Pears will not be a success if there is too much exposure to wind. The best results are got by growing pear trees on a wall facing south, or west, to provide shelter and extra warmth.
Ideally, the soil should be deep, free-draining, moisture-retentive and fertile. Pears tolerate heavy soil better than apples and dislike dry conditions at the roots. If the soil is poor, for wall trees it is worthwhile removing the top 50 centimetres of soil over an area of one square metre, and replacing it with good soil mixed with well-rotted manure, compost or peat.
Pears: varieties and planting
The best variety is 'Conference' - it is the most reliable. It needs a pollinator and two good possibilities are 'William's Bon Chretien' and 'Doyenne du Comice'. The variety 'Concorde' is a hybrid of 'Conference' and has good characteristics too.
November to March is the planting period and November is the best month. Remove, or spray off, the existing grass or weeds and dig the soil over a square metre or so. Incorporate a couple of bucketfuls of well-rotted manure or compost at the site for each tree.
Buy the trees and soak the roots before planting. Dig holes 45 centimetres wide and 30 centimetres deep. Drive a stake in each hole to support the young trees. Trim any damaged roots. Test the tree in the hole for depth, and plant at the same depth as the soil mark on the stem. Fill in and firm gently. Tie each tree to its stake.
Space cordon trees about 150 centimetres apart; fan, espaliers and spindle bushes about 240 centimetres apart; and free-standing pyramid trees about 4 metres apart.
Pears: training
The restricted shapes - cordon, fan and espalier - suit pear trees well. They can be trained as cordons on wires, or as espaliers or fans on a wall or fence. Train them to shape, tying in young shoots in the correct position and removing surplus.
As free-standing bushes, pears quite naturally take on a pyramidal shape. Tie in a central stem to the stake and allow side branches to develop to form the pyramidal shape. Remove badly placed branches. Pears can be slow to bear fruit and often take between three and seven years to begin. Much depends on the site and soil conditions and the size of the tree when planted.
Pears: pruning and feeding
Pear trees carry most of their fruit on short spurs on older branches. Once pears settle down to fruiting they need very little pruning; just remove dead, damaged or diseased branches, and an old branch here and there if there is crowding or the tree is getting too big. Remove some of the old fruiting spurs on restricted trees to improve fruit size.
However, if a pear tree does not carry a crop, its vigour goes into producing branches instead. Summer prune the surplus strong young growth by removing about half of the number of shoots and shortening the remainder to about 10 centimetres during late summer. Wall-trained trees are most likely to need this treatment.
Pear trees should be given 70 grams of general fertiliser per square metre in March if they are carrying a good crop. If the trees are over-vigorous, apple sulphate of potash at a rate of 30 grams per square metre instead. A mulch of rotted compost every few years is beneficial by conserving moisture in summer, but should not be applied to over-vigorous trees. Feed and mulch old trees to get them growing again.
Pears: thinning and picking
Thinning is not usually necessary, but sometimes the variety 'Conference' produces too many fruits. Reduce the fruit to one per spur, or two if many of the spurs have no fruit. Early July is the time to thin.
Pears do not ripen on the tree. They mature, then fall off and ripen on the ground. Pick the fruit when it looks mature, and put it in a cool place, indoors. Pears will soften for eating within a few days or a few weeks, depending on variety, but do not continue to store them once they have softened.
September-ripening kinds, such as 'William's Bon Chretien' ripen after a week or so off the tree. 'Conference' matures later and can take a few weeks to soften. If pears are picked too soon, they tend to simply dry up and wither without softening. If they are picked too late, the fruit softens quite quickly but soon develops brown mushy flesh at the centre.
Pears: weeds, pests and diseases
Keep the ground free of weeds by hoeing, or using Simazine each March. A mulch will help to keep down weeds. Pear trees crop better when not grown in grass, even when established.
Greenflies may attack, and may need to be controlled. Pear midge is a little fly whose maggots bore within the fruit, hollowing it out and causing it to fall early. Though not very common, this pest can be troublesome. Destroy all the early fallen pears. Birds may attack both fruit and buds.
Pear scab is the most common disease and causes black spots and cracking on the fruit. Though it is not as widespread as apple scab, precautions may be necessary in wet seasons and in wet, cool localities. Cracking can also be caused by sudden changes in the weather or by drought.