One of the most important reasons to prune walnut trees is to encourage fruit production. But this is not unique, as other objectives of pruning are to facilitate harvesting, direct growth and formation of trees, improve ventilation and facilitate the penetration of sunlight. Young walnut trees are pruned in their early years to determine their structure. Shaping trees is critical because it affects the quantity and quality of crops, ease of harvesting, and other farming activities. Many people don't know how to prune a walnut tree.
For this reason, we are going to dedicate this article to telling you everything you need to know about how to prune a walnut tree, when you should do it and what aspects to take into account.
walnut pruning
Pruning mature walnut trees to maintain their structure and clean the interior of the tree improves sunlight penetration and ventilation inside the plant. All of these activities benefit the production of nuts in future harvests. Pruning of mature walnut trees is done annually or every two years.
When it comes to pruning walnut trees, we must take into account some criteria. If there is something that we have to take into account when planning the pruning of walnut trees, it is the forecast of frost after pruning. Like other fruit trees, Walnut trees can suffer tissue damage if a frost occurs after pruning. Therefore, whenever there is a risk of frost (temperatures close to 0 degrees), pruning should be postponed until the risk disappears.
Therefore, it is always necessary to try to align the pruning with the times when the tree is dormant. Generally, a good time to prune a walnut tree is it late winter or early spring, before the tree becomes active again, if frost is not expected. This will reduce sap loss, and as the growth phase approaches, the wound will soon begin to heal. In climates with slightly cooler winters, fall pruning may be a good option.
While important pruning, such as formation, production or regeneration, should be done during the cool season, green pruning is not. A good time to green up walnut trees is in early to mid-summer, when it is warmest.
what tools do i need
To learn how to prune a walnut tree you will need several tools, depending on the size of the tree and the type of pruning you want to do. Here is a list of some walnut tree pruning tools:
- One-handed pruning shears: We can use it to cut branches up to 2,5 cm in diameter. These scissors are more recommended for pruning greens.
- Two-hand scissors: We can use it to cut branches up to 5 cm in diameter.
- They are used to saw branches between 5 and 20 cm in diameter. For larger branches and trunks we will need a chainsaw.
- Chainsaw: They are used to cut thick logs over 20 cm. There are electric chainsaws and gasoline chainsaws that use batteries or power cords. This is the name of the scissors, saw or chainsaw with a telescopic handle that can reach the highest branches. With these tools we can cut branches at a height of about 5 or 6 m.
- Stairs: It is important to follow safety rules and not swing at the top of the ladder. Remember that you must go down a few steps and your waist should not exceed the last step. In such missions, falling from heights is dangerous.
- Security elements such as gloves, goggles, equipment, boots... don't forget to protect yourself and work safely.
- It is recommended to sterilize the knives before cutting them. This will help prevent fruit tree diseases.
How to prune a walnut tree
To prune a walnut tree, we first need to know the type of pruning we are going to do, and for this we need to know the age of the fruit tree. Pruning a young walnut tree that is growing and needs training to prune it is not the same as pruning an adult walnut tree, it will be necessary to think more about production and enhance the harvest.
How to prune a young walnut tree
Young walnut trees require formation pruning to establish a central axis for the rest of the tree to grow. We can say that a walnut tree is young when it is less than 5 or 6 years old. This is relative, since the trees vary more or less according to the region, the climate, the variety...
Pruning during this growing season is to guide the growth of the tree and define its structure. We will see the type of pruning that we have to carry out at this stage of development:
Formation pruning
It includes directing the structure and growth of the tree during the early years. As this is a fairly vigorous pruning, do it when the tree is still, that is, in early spring, or in autumn in areas where the winters are not too cold. Shaft formation trimming is done as follows:
- During the first year, we must prune all the branches of the tree to promote sprouting of the lower branches.
- The main branch appears in year 2. We leave the lower branches, except those that sprout from the lower half of the trunk.
- In year 3, we can the main branch to 2/3 of its length and remove the branches that grew into the cup at an open angle.
Fruiting pruning
Its purpose is to establish secondary productive branches. It is about choosing the 3 or 4 main branches where we want the rest of the tree to grow. The slope of the main branch should not be too high to prevent it from breaking under the weight of the crop in the future. In this way, we will prune the suckers that grow from these branches, we will cut them a little to about 2/3 of their length, thus establishing the structure of the tree.
How to prune an adult walnut tree
Pruning an adult walnut tree to maintain its shape and clear the interior of the tree promotes ventilation and light inside the canopy. It is called production pruning, although rejuvenation pruning and green pruning can also be done at this stage.
Production pruning
This pruning is done to take advantage of the amount of sunlight captured by the crown, maintaining its shape to improve the quality and quantity of the harvest. It is to clean and clarify the branches to facilitate the entry of light and facilitate the fruit. Split cups are preferable to spherical cups because they increase the exposure area, making the most of the light. Unproductive branches or suckers should also be removed, as well as side branches growing inside the tree.
As we said, with all this, in addition to ensuring a higher quality fruit, the yield of the trees has also been improved. We will proceed as follows:
- First, we will remove the largest suckers, as they are not very productive and will suck the sap from the branches from which they sprout.
- We will leave the weakest suckers or buds inside the tree to shade the tree structure.
- We have to prune the lower branches because they receive less light and therefore bear less fruit.
- The cup should be leaf-shaped with many inlets and outlets for Increase exposure and make better use of light. We will also remove branches with very sharp angles.
- To maintain the leaf-to-wood ratio, excessively intensive thinning of twigs should not be carried out. Therefore, we will avoid excess wood, which reduces the regeneration and formation of productive branches.
Rejuvenation pruning
Rejuvenation pruning, also known as renewal pruning, is performed on trees that show signs of aging after a long period of production (20 to 40 years). These symptoms can be:
- smaller leaves
- yellowish color
- loss of leaves inside the tree
- low production
It is an energetic pruning that rejuvenates the walnut tree, although it can also be done gradually.
- Substantial Rejuvenation Pruning: In the first case, what we do is remove all the leaves from the tree, effectively leaving the base and main branches of the trunk to grow back.
- Progressive rejuvenation pruning: It consists of pruning from the top of the crown to the base of the branches. It is done in stages, every 3 years we will cut one of the four main branches of the tree.
Pruning in green
Renovation pruning or green pruning can be done in summer. Although it can be done at any time of the year, it is usually done at the end of August, when the walnut trees have little activity due to the heat. This is done to control the growth of suckers or suckers, removing those that are not available to the walnut trees.
What is done with the remains of pruning
After the pruning is done and not all the work is done, we still need to remove the remains of the branches. But how do we treat them? …well, we have a few options:
- Use a tree shredder. This type of machine makes life easier for us and is also ideal for enriching the soil with organic matter since the crushed material can be spread over the field. Today, a home chipper is available in any pocket on the market.
- burn the branches. To do this, we have to request a permit from the town hall where the walnut plantation is located. Some days fires are not allowed, so we had to inform ourselves in advance and request the corresponding permits.
- To make firewood for stoves, ovens, fireplaces, etc... To do this you must prepare the remains of branches and trunks, chop them and make small pieces, remove the leaves, and sprinkle them on the crops. For example, this wood can also be sold to businesses that require a wood-fired oven, such as bakeries, pizzerias, etc.
I hope that with this information you can learn more about how to prune a walnut tree and what you should take into account for it.