Cherries: acid

Acid cherries (Prunus cerasus) are less vigorous than sweet cherries, growing to a height and spread of 3-3.5m (10-12ft). They are usually grafted onto the semi-vigorous ‘Colt’ rootstock, which limits their height and spread to a manageable size.

Acid cherries are self-fertile, so do not need a partner tree to act as a cross-pollinator. They tolerate some shade, making them a suitable choice for fan-training against north facing walls and fences. Alternatively, grow as an open centred bush tree. Cherries are too vigorous to be grown as espaliers or cordons.

Planting, soil, watering and feeding requirements are the same as for sweet cherry. See the links below for details.

The initial training for an open centred bush tree is the same as for sweet cherry. Initial fan training is also as for other fruit trees.

Unlike sweet cherries, acid cherries bear almost all of their fruit on the growth formed the previous season. Once the tree is mature enough to fruit, the aim is to achieve a balance between one year old fruiting wood and new replacement branches. This is known as replacement pruning.

Cherries (and other stone fruit) should not be pruned during winter, to minimise the risk of infection by silver leaf or bacterial canker. Light formative pruning can be carried out in spring as the leaves start to develop, but the time to prune established acid cherry trees is in late summer.

Pruning of established bush trees

• Stimulate new growth by cutting back, in late summer, about one in four of the older fruited shoots, pruning to a younger side shoot that can replace the removed growth
• Shorten over-vigorous upright growth that crowds the centre to a suitably placed side shoot

If left un-pruned the branches will become lanky and only fruit at their ends.

Pruning of established fan-trained trees

• Thin the new shoots formed along the main branches to 5-10cm (2-4in) apart and tie the retained shoots to their supports in early summer
• Prune back branches that come out from the wall to two leaves, to keep the tree flat and allow better light penetration
• In late summer tie in the current season’s growth that will flower next year
• Cut back the fruited shoots to a suitable side branch that can replace the removed growth

Cherry trees are generally propagated by grafting. Named cultivars will not come true from seed. Trees grown from seed or cuttings will be much larger trees than those grafted onto a chosen rootstock, and will be slower to start fruiting.

‘Morello’ AGM: Self-fertile, excellent flavour, for picking in late summer.
‘Nabella': Self-fertile, for picking in late summer.

Links

RHS Find a Plant
AGM fruit

If flower bud or immature fruit drop occur, then drought, waterlogging, low temperatures, or bird damage are the likeliest causes.

Other problems include aphids cherry blackfly, winter moth caterpillars, pear and cherry slugworm, bacterial canker, blossom wilt, brown rot, silver leaf and magnesium deficiency.

The fruit fly - spotted wing drosophila (SWD) - is likely to become an increasing problem.

Apricots
Cherries: sweet
Cherry fruit drop
Cherry leaf scorch and leaf spot
Fruit: growing in containers
Mulberries (Morus nigra)
Plums
Plums, damsons and gages: choosing cultivars
RHS video: Growing cherries