In the early 1990s, the technique of « Juniknip » (June Cut) for apple trees was rediscovered. This summer pruning method helps improve fruit ripening, controls excessive growth, and reduces the risk of fungal diseases.
Why Summer Pruning Matters
One of the essential care practices for apple trees is pruning, especially during the summer. Summer pruning regulates the tree’s growth, reduces the risk of fungal infection, and ensures better fruit development. When the tree is pruned properly, rainwater evaporates faster from the leaves, and the tree’s crown remains better ventilated, reducing the chance of disease. Additionally, better light penetration allows for more even ripening of fruits inside the crown, which enhances their flavor and aroma.
The June Cut Explained
The primary focus of the « Juniknip » involves removing water shoots (one-year-old vertical shoots), cutting back the unbranched tips of the main trunk and side branches, and promoting air circulation within the tree. These measures slow down the growth of the tree and encourage better bud formation. The optimal time for this pruning is between late June and mid-July, as this period follows the completion of the tree’s growth and before the tree starts forming new buds for the following year.
How to Perform the June Cut
- When to Prune: Prune the apple tree between late June and mid-July. During this period, the tree has finished most of its vertical growth, and new buds for next year are beginning to form.
- What to Cut: The focus should be on removing the vertically growing, one-year-old water shoots (also known as « water suckers »). For weaker-growing apple varieties, leave the thinner branches in the crown and only remove the thicker, stronger shoots. If you remove too many shoots, the tree will have insufficient energy to nourish the fruit, leading to smaller apples.
- Pruning Technique: For the main trunk and side branches, cut the unbranched tips just above a downward-facing bud. This encourages new growth and the development of lateral branches that will later bear fruit. Water shoots, which typically grow vertically on the upper side of branches, should be cut off at their base, as they compete with the fruit for light and provide little to no fruit wood.
- Removing Water Shoots: Thin, less woody water shoots can be removed easily by tearing them off. This is beneficial because tearing causes less damage to the tree than cutting and promotes faster healing of the wound.
Fruit Thinning for Optimal Growth
Some apple varieties, such as ‘Boskop,’ often exhaust their energy during flowering and fruit formation, leading to fewer buds for the following year. To avoid this alternate bearing (where the tree produces fewer apples in the following year), thin out the fruit in late June. A good rule of thumb is to leave one or two apples per cluster. These will grow larger and are better nourished, leading to higher-quality fruit.
Tips for Smaller Trees and Espaliers
For smaller trees or espalier apple trees (trained to grow against a wall or fence), the expert advice is to « bind rather than cut. » This technique helps develop flatter, more productive branches. Instead of cutting, use weights or gentle ties to bend the branches downward, ensuring that the ties don’t damage the bark. This encourages early fruit and flower production.
Conclusion
Summer pruning of apple trees, especially through the June cut, is essential for ensuring healthy growth and high-quality fruit. By understanding when and how to prune, you can keep your apple trees thriving while minimizing the risk of disease and promoting better fruit development.