Apples and pears: growing and training as cordons
Cordons allow you to grow a useful amount of fruit in even a small garden. Cordon training is suitable for all apples and pears that bear fruit on short sideshoots (spur-bearing).
Timing Plant in winter, prune in summer
Cordon training is suitable for all pears and apples that bear fruit on short sideshoots (spur-bearing). The term 'cordon' simply refers to a single stem with short sideshoots (the fruiting spurs). This is usually trained angled to 45 degrees (oblique cordon), but can be trained singly vertically (sold under a variety of names such as Minarette®) or horizontally (stepover). Alternatively, they can be trained as multiple vertical 'U' or double 'U' cordons. Angled (oblique) cordons are more productive and less prone to getting out of hand than vertical cordons. They are trained against a wall, fence or on wires between free-standing posts.
Unfortunately, vigorous cultivars are difficult to keep within bounds so make poor cordons. Likewise, cultivars that bear fruit at the tips of their branches (tip-bearing) are difficult to train in this way as the tips need to be pruned off and so little fruit is borne. Those apples and pears that bear fruit on both tips and side shoots, known as partial tip-bearers, can be grown as cordons if some short branches are left unpruned each year. For example ‘Discovery’ and ‘Charles Ross’ can be successfully gown as cordons. Others such as ‘Worcester Pearmain’, ‘Bramley's Seedling’ and ‘Cornish Gilliflower’ are less successful.
Support system, planting & initial pruning
Choose an open, sheltered position, avoiding frost-prone sites, if possible. Soils should be well-drained, moisture-retentive and not prone to waterlogging.
The best time for planting cordons is in winter. Use one-, two- or three-year-old cordons. When buying cordons, you will have a choice of rootstocks. Use M27 rootstock (extremely dwarfing) or M9 rootstock (very dwarfing) for apples where the soil is fertile; otherwise, use M26 rootstock (dwarfing). Pears are best grafted on Quince C or, for very poor soils, Quince A. If in doubt, use a more dwarfing rootstock as it is always possible to boost vigour with watering, feeding and mulching if required.
Cordons need a permanent support system made up of three horizontal wires 60cm (2ft) apart with the lowest wire 30cm (1ft) from the ground. If planting against a wall or fence, fix the wire using straining eye bolts that will let the wire be fixed not less than 10cm (4in) away from the structure to allow for air circulation. Keep the wire taught with straining bolts available from fencing suppliers. Use a sturdy 2.5mm, gage 12 galvanised wire.
If using posts, the posts should protrude 1.8m (6ft) from the ground with about 60cm (2ft) below ground, spaced 2.2-3.5m (7-12ft) apart. The end post should be strutted. Fix bamboo canes diagonally to the wires for the trees to be trained on.
Plant trees at an angle of 45 degrees. If planting more than one cordon, space at 60-90cm (2-3ft) apart. The wider spacing within the row is for infertile, shallow or sandy soils. Tie the cordon to the diagonal bamboo cane fixed to the wire support with a soft string. Cordons can be allowed to reach a height of about 1.5-2m (5-6½ft) so take that into consideration when planting.
After planting, cut back all laterals (side shoots) longer than 10cm (4in) to three buds, leaving the leader and any short laterals unpruned.
Vertical and double cordons (‘U’-shaped) can also be grown in containers (at least 45cm (18in) wide) in John Innes No. 3 compost (a soil-based potting media that is easy to manage and heavy enough for the pot to be stable).
How to prune and train a cordon
Summer pruning an oblique cordon (at 45 degrees)
Summer pruning is carried out in August, or in areas where growth is strong, such as wet parts of the country, delay summer pruning until September when a large terminal (end) bud has formed at branch tips and the tree has stopped growing.
- Look for sideshoots over 22cm (9in) long (length of a pair of secateurs), which grew earlier in the summer directly from the main stem, and cut them back to three leaves beyond the basal cluster (cluster of leaves at the base of the current season’s growth). Those stems that grew from existing sideshoots or spurs can be pruned harder - to just one leaf beyond the basal cluster
- Leave shoots less than 15-22cm (6-9in) long until mid-September and then shorten to one leaf beyond the cluster of leaves at the base
- Prune any growth that forms after summer pruning in September (or October if pruning later). Prune to one leaf beyond the last cut
- Tie the leading shoot ('leader') in to the support until it reaches the required length. Thereafter, prune it back and treat subsequent growth as for other laterals
- When the cordons reach the top wire they may be lowered from 45 degrees to not less than 35 degrees (as there is less risk of the stem breaking) in early spring. This will increase the length of stem, and so the amount of fruit produced. Again, once the cordon has reached the top of the support, prune it back in late summer and treat subsequent growth as for other laterals
Winter pruning oblique cordons
- Neither the leader nor side shoots are normally pruned in the winter, except where the tree has grown a lot since summer pruning or you need to renovate a neglected tree
- Over time the spur system can become over-long or complicated. Remove older and unproductive sections of the spurs. Occasionally rejuvenate the spur system by pruning back to a stub 3-5cm (1-2in) of the main stem cutting above a well-placed dormant bud
How to prune Minarette® and Ballerina® (columnar) trees
Vertical cordons, including Minarette®, lack the inhibiting effect that the angling and bending of the stems provides on oblique and double cordons. As a result, they are harder to train and prune because they want to turn into small trees. However, they are still useful in small gardens so here are some growing tips:
- Plant ready-formed Minarette® or maidens (a young tree without the development of side shoots)
- Tie to a vertical, 2.4m (8ft) tall bamboo cane
- Allow at least 60cm (2ft) between trees. Close planting 60-80cm (2ft-32in) helps to restrict the vigour
- Encourage the lower buds to break on maidens by shortening the leader by one-third of its height each winter until it reaches the top of the stake
- Otherwise, prune as for the oblique cordon (above)
- Such training can also be useful for training trees over arches
Growing the trees as vertical double (‘U’) or four-armed (double ‘U’) cordons may be a compromise as they are still ‘space saving’, but the vertical dominance is reduced. Pre-trained trees are often available for sale.
Ballerina® or ‘columnar’ apples have been bred for a columnar habit that needs no pruning other than occasional shortening of sideshoots and the leading (top) shoot. Thin out spurs in winter when congested.
Ballerina® trees are convenient in small gardens or where pruning skill is uncertain. Unfortunately, Ballerinas® are reputed to have less flavour than conventional apples and are also more prone to disease.
- Lack of side shoots: Cut back the leader (last summer’s growth) by up to one-third in winter to induce some of the lower buds to break
- Neglected cordons: Renovate by winter pruning followed by summer pruning. If badly neglected, spread the winter rejuvenation over a couple of years. Such trees may be best replaced.
- Bare wood lower down: To encourage dormant buds to break, a method known as 'notching' can be tried. This requires a small line to be scored, to the hard wood underneath, with a sharp knife immediately above a latent bud and a crescent-shaped piece of bark removed. This releases the bud from dormancy due to the effect on flow of plant hormones within the plant and enables the dormant bud to grow. Where this fails, there is little else that can be done to regain the original shape
Cordons can suffer from the same pest, disease and cultivation problems as standard or bush grown apples and pears however their small size makes control methods more practical.
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