JAS - the best time for pruning
July, August, and September (JAS) are good months for pruning most bushes and trees in the garden. This is when the plant is in full growth and we can see the plant's shape with its foliage. For the varieties known as 'bleeders', this is the only time of year suitable for pruning.

Why should you prune?
- Pruning provides airier and fresher bushes and trees. This results in a reduced risk of diseases.
- Removing dead and damaged branches that look unsightly and can be an entry point for diseases.
- It leads to new and healthy growth.
- It gives a finer and more even shape to the plant.
- More fruit and berries.
- Healthy, young branches produce more berries and fruit than old branches.
Why prune during the JAS period?
Typically, most bushes and trees in the garden are pruned in late winter or early spring, especially apple and pear trees, as it can be easier to access up in the trees, but primarily because the gardener had time then. Through research and practical experiments, it has been found that the plants thrive better when pruned in July, August, and September. At that time, the bushes and trees are still growing, and the wounds from pruning heal faster.
For the varieties known as 'bleeders,' such as hornbeam, maple, magnolia, Japanese cherry, and beech, the JAS period is the only time of year suitable for pruning. In bleeders, the sap rises in the trunk in late winter and early spring, and then there is a risk that it will run out of the cut surfaces and open up to diseases and rot.
Basic pruning tips
- Remove dead and damaged branches.
- Make the cut at a point where the bush/tree has good conditions for new growth. That is, above a young bud or side branch that extends out from the trunk.
- Consider the plant's natural growth pattern. Place the plant in a location where it naturally thrives rather than trying to make the plant adapt to your needs.
- Cut away thin, weak branches that grow into the crown or branches that rub against each other. Cut off long shoots that disrupt the overall appearance.
Pruning bushes
- Rejuvenation Pruning of Bushes
Cut away one-third of the plant right down to the ground. The following year, cut away the next third, and so on. It's also possible to prune everything at once, but it's a greater strain on the plant. - Berry Bushes
It's fine to thin out berry bushes after harvesting. Remove the oldest branches right down to the ground, as well as branches that lie against the ground. Summer raspberries bear fruit on last year's shoots, that is, the branches that are in their second year. After harvesting, these branches are cut away completely. Autumn raspberries produce berries on this year's shoots, so the plant is cut down completely after harvesting. If you have currant bushes and want more, you can propagate them through so-called layering. Take a branch that is low and cover the entire branch except the top with soil, secure with a stone or staple. The following autumn, the branch has rooted, and you can cut it off from the bush and plant it. In the same way, you can propagate rhododendrons, for example. - Grapes
Grapes are pruned in the autumn after harvesting. Then, you cut off the shoots that have grown out during the summer. You can save leaf pairs or buds from the previous pruning, depending on how large and wide a bush you want. It is only necessary to prune grapes if you want grapes. The grapevine is also a decorative climbing plant that can be grown to cover a pergola or wall, and then it is not necessary to prune it.
Pruning fruit trees
- Rejuvenation Pruning of Fruit Trees
Older apple and pear trees need rejuvenation pruning. Cut away one-third of the water shoots, i.e., the branches that grow straight up, in the first year and continue like this in the following years. Old branches are also pruned in a multi-year plan. Remove dry and dead branches, as well as branches that cross each other or point inwards towards the crown. The tree then has time to come into balance and resume fruit setting. It is important to have an even distribution of branches of different ages for the tree to bear appropriate amounts of fruit. Apples and pears can also be pruned carefully in late winter and early spring. Heavy pruning will cause the tree to shoot many new shoots, primarily "water shoots" that grow straight up. These branches do not produce fruit; they only take energy from the tree. Stone fruits such as plums and cherries are pruned as needed after harvesting, i.e., primarily in August and September. - Regular Pruning
A mature fruit tree that has started producing fruit must be kept in balance between fruit setting and growth. Regular pruning provides this balance along with fertilizer, such as garden fertilizer.
With the right tools, the job is easier
The pruning job becomes more enjoyable and yields better results if you use the right tools that are well-sharpened. Pruning shears that fit comfortably in your hand, loppers, and possibly a pruning saw are a good start. Avoid using a carpentry saw (handsaw) for pruning. It gets stuck easily and leaves rough cut surfaces.
The weight of the tools matters if you're doing a lot of pruning. It can become tiring in the long run to work with hedge shears or loppers that are too heavy. An electric hedge trimmer might make the job faster and more comfortable if you have a long hedge to prune.
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