A plum tree can live for several decades. However, its fruit shoots age quickly. After just a few years, they are so exhausted that the yield decreases noticeably. If you don’t want to do without the delicious fruit, you have to stimulate the plum tree to form new fruit wood in good time. This is done by appropriate cutting measures. Knowing when which branches have to give way is of crucial importance. You can find out when and how to properly prune a plum tree here.
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The fruit wood on the plum tree
The plum tree, bot. Prunus domestica , but also the related plums , greengage and Mirabelle plums are very similar in their growth and flowering characteristics. Therefore, a similar cut and the same recommendation applies to all three types: cut back intensively. This has to do with the fact that their fruit wood ages quickly. The amount of fruit decreases or the fruit gets smaller on such exhausted branches.
- two- and three-year-old shoots bring the highest fruit yield
- after 4-5 years the fruit shoots age
- Prunus domestica must form new fruiting wood regularly
The different types of cuts
When pruning plum trees, damsons and the like, a distinction is made between three types of pruning depending on the objective. These are:
- education cut
- maintenance cut
- taper cut
The three types of cut differ from each other in terms of the time at which they are carried out and the selection of the shoots. While the maintenance pruning is necessary at regular intervals throughout the life of the tree, the educational pruning is carried out at the beginning of the planting and the rejuvenation pruning only when necessary.
education cut
Prunus domestica is usually planted in autumn because that is the ideal time for it. Container goods should also preferably be planted at this time, although this is theoretically possible all year round. The tree has enough time until spring to take root and is ready for the first cut. This is used for scaffolding. If you plant a plum tree in spring, you should train it immediately and not wait until next spring. The following are the key points of the guide:
- Spring is the best time for the training cut
- leave a strong center drive
- additionally select up to four side stand shoots
- remove all other shoots
- Shorten all scaffolding shoots in half
- about the same height so they stay in juice scale
- pay attention to the position of the top buds
- they must point outwards in the case of side scaffolding shoots
- in the case of the central shoot, the bud stands above the base of the middle
- about 15 to 20 cm above the juice scale
- continue shortening the next 5-7 years
- this strengthens the scaffolding drives
- in the case of the middle shoot, the top bud must always be above the middle
- albeit in contrast to the previous year
The side branches will form the crown. In order for this to be stable, branches with different heights should be selected. In these first years, only the skeleton shoots are shortened on Prunus domestica. Fruit shoots, on the other hand, are not shortened, but slimmed down if necessary. A maximum of 8 side shoots growing outwards should remain as future fruiting wood per main branch. Otherwise, the shoots shade each other.
Time for maintenance pruning
After the desired crown structure has been achieved with the training cuts and the yield phase begins, Prunus domestica must be cared for regularly with a maintenance cut. You don’t have to prune your plum tree annually, but at least every two years.
- Summer is the ideal time
- the wounds are healing well at this time
- cut immediately after harvest
- avoid dry and hot periods
- the thinned inside of the crown can get sunburned
- summer pruning should be done by mid-September at the latest
Instructions for the maintenance cut
Plums and damsons are often not distinguished by laypeople. And so a plum tree is often referred to as a plum and vice versa. For the summer cut it is irrelevant. However, it is crucial to gain a precise overview of the crown structure before the pruning measure and to assess the effect of each branch removal or shortening well. Because in summer plums and damsons are still covered with leaves. Walk around the tree to get an overall impression. Bend individual branches to the side to be able to better assess their position or the consequences of a pruning measure. Here are the steps for the maintenance cut:
- First, remove any steep shoots.
- Also cut off any shoots that grow into the interior of the crown.
- Check whether individual fruit shoots are growing very vigorously and are competing with the side shoots.
- Remove these competing shoots on cones. Alternatively, you can redirect them to flat side shoots close to the trellis.
- Also direct three-year-old or older fruiting wood to younger shoots that are further in. However, the young shoots should be at least two years old and bear fruit. Then the growth stops.
- Strongly branched fruit shoots and skeletal shoots must also be diverted. Redirect the strongest overhanging branch to a side shoot. This should grow flat or slightly sloping.
- If necessary, slim down the new tips. This means that you remove the side shoots at the top of the shoot.
Time for the rejuvenation cut
Rejuvenation pruning is performed only when necessary, when almost all of the tree’s branches are very old. With it, a new vital and, above all, fruit-bearing crown is built up. If you prune your plum tree regularly, you will hardly ever have to do a rejuvenation pruning. Sometimes, however, the maintenance cuts were not carried out for several years. Or a garden with an overgrown plum tree was taken over. Then a makeover cut can breathe fresh life into it.
The taper cut is one of the types of cuts that are best performed in summer. Then it is better tolerated. The cuts heal faster and an exaggerated new growth is not to be expected. On this day, however, it should neither rain nor be excessively hot and dry. Alternatively, it is also possible to prune from October to the end of February.
Taper Cut Instructions
Here are the instructions for the non-annual and therefore not so familiar cut. Because the branches are not simply cut away by feel.
- First remove dead branches and twigs.
- Then all the steeply rising shoots are turned. If their diameter at the cutting point is more than 5 cm, cut them into cones 10-15 cm long.
- Divert senile, overhanging brooms to side shoots. A side shoot that points outwards and is further inwards is ideal.
- Also redirect senescent and heavily branched fruit wood. Vital shoots close to the framework are ideal for this. If there is no vital shoot available for the diversion, then cut back the senile fruit shoot to a 10 cm long spur. New shoots will sprout at the base of the cone.
- After the tree has sprouted again, the young shoots must be pruned. Remove the steeply growing specimens, while flat shoots can remain as fruiting wood.
Cutting on tenons
Once again the hint why the “pruning on cones” is so important with plum trees. It may be necessary to remove larger branches, especially when a rejuvenation cut is pending. However, the cutting points in plums, damsons and other related fruit trees dry deeply. Wood-decomposing fungi settle and can spread to healthy branches before the wound can be closed. That must be prevented.
- avoid large interfaces
- they should have a maximum of half the diameter of the remaining main drive
- Keep interfaces at a distance from healthy wood
- therefore leave 10 to 15 cm long cones
In the meantime, the main shoot has the opportunity to increase in thickness. After about 2-3 years, you can cut back the dried cones to the first vital young shoot. The tree is then able to close the wounds faster. The best time for this is summer, during maintenance pruning.
