Planting, pruning and caring for walnut trees

The walnut tree is popular with many people mainly for its delicious fruit. You can find the most important facts about the walnut tree here.

The walnut tree is a very impressive tree with its stately size and the very robust and undemanding species. With enough space, a warm location and a little patience, it can be an asset to meadow orchards or gardens.

Walnut tree: profile and origin

The historic home of the walnut tree (Juglans regia) is in ancient Rome. In the meantime, the "divine fruit of Jupiter" is widespread not only in the warm Mediterranean region, but throughout Europe. Their love of warmth was weakened by breeding, so that there are now private and commercial walnut tree plantations in this country. The walnut tree belongs to the walnut family (Juglandaceae) and is best known for the popular walnut.

The walnut tree leaves are imparipinnate and consist of 7-9 leaves. The male walnut tree flowers have a special shape with their long and snake-like inflorescences. With enough space, it can be a great enrichment for animals and humans. If you have little space, planting a walnut tree in the garden may be prohibited because it grows very large and wide. On the other hand, large and old walnut trees are protected and may not be felled without permission. This applies in particular to urban areas. The reason: If you research which animals live in the walnut tree, you will uncover a remarkably long list. Squirrels, dormouse, protected corvids, rodents and various insects benefit from a walnut tree in the garden.

The most popular walnut tree varieties

There are different types of walnut tree: They differ in terms of their growth, their resilience, the time of ripening, the fruit characteristics and the time of budding.
The walnut tree varieties ‘Mars’ (Juglans regia ‘Mars’) or ‘Franquette’ (Juglans regia 'Franquette') are particularly resilient and, due to their late budding, not very sensitive to late frosts. In the case of grafted plants, yields can be expected in regularly high quantities from the third or fourth year. The 'Franquette' is a rather slow-growing variety. Another new variety with a good yield is the 'Buccaneer', which also buds late. Other varieties that sprout late and are therefore also suitable for cold locations are the 'Geisenheimer Walnut' or the 'Weinheimer Walnut'. The varieties 'Jupiter' or 'Esterhazy II' are more suitable for warmer locations due to the early budding.

For smaller gardens, there are a variety of dwarf walnut tree varieties such as the ‘Europa’, which only grow to around 3 to 4 meters tall.

Plant walnut tree

The ideal location for a walnut tree is warm and sunny, with plenty of light. In addition, the walnut tree needs enough space and distance because it can develop a very large crown. At the same time, a distance of at least 5 to 10 meters to the neighboring property should be maintained - if you have this space not, planting a large walnut tree in the garden is forbidden, at least according to the rules of border planting in the neighborhood law. Very little grows in the places where the leaves and husks of the walnut tree fall off. This is due to the active ingredients it contains, which microorganisms can convert into the tanning agent juglone. This can inhibit the growth of other plants.

The soil should be deep, well aerated and rich in nutrients. The planting hole for the walnut tree should be at least 1.5 times as wide and deep as the walnut tree roots in the ball. The planting hole can then be filled with mature compost or high-quality potting soil like ours Plantura organic universal soil filled and mixed with the excavation. Our universal soil is ideal for outdoors because it is safe for all garden animals and enhances soil that is too heavy as well as too light.

You can then tie the tree with one or two stakes, depending on its size. Finally, the ground around the trunk is well-trodden and the tree is poured with water.

The ideal time to plant a walnut tree is in spring or autumn. This should preferably be done after or before frosts occur, as the young plants are still very sensitive to frost. If you plant your walnut tree in autumn, it has the advantage that it can still develop fine roots, which are helpful for absorbing water in spring and summer.

The height of the walnut tree can amount to 15 to 25 meters in old age.

Care of the walnut tree: pruning, fertilizing and Co.

Walnut tree care is not difficult at all if a few important points in the areas of pruning, fertilizing and watering are observed.

Cut walnut tree

As a rule, walnut trees only need to be pruned a little. When the crown and branches become very sprawling, pruning may be necessary to maintain the walnut tree's shape and contain some spreading. To do this, only competing branches that grow in the same direction or rob each other of light or space should be shortened. Cut these at the front junction to avoid causing too many cuts. The walnut tree can often "bleed" at the cutting points, which is why pruning between the end of June and the end of September is recommended. The cut should not result in a horizontal surface so that there is no water on the wound. Walnut trees are pruned to astring, so no "stub" should be left. A rejuvenation cut in old trees is only possible to a limited extent due to the large wounds that are produced.

Fertilize and water the walnut tree

When it is dry, it may be necessary to water your walnut tree. Sufficient watering in the first few months is particularly important for young plants that do not yet have a well-developed root system. The tree should not be watered that often, but it should be watered vigorously.

Walnut trees are very undemanding, they have a comparatively low nutrient requirement and require little phosphorus. A needs-based supply is, for example, with our Plantura organic flower fertilizer possible, which contains relatively much potassium and nitrogen, but comparatively little phosphorus. Because these nutrients are mostly organic, fertilization is done slowly and gently. Alternatively, compost can be used, but the rotting material should not be too fresh - this is often far too rich in nutrients. A good time to fertilize walnut trees is after the fruit has dropped.

Tip: Annual maintenance should also include removing and discarding foliage and old fruit peel. Because diseases can spread from these in the coming spring again.

Propagation of the walnut tree

Walnut trees can be re-cultivated via the nut. For this purpose, it should be as fresh as possible and can either be put directly into the ground in its future place in the bowl or grown in a pot. Outdoors you often have problems with mice, which makes growing in pots more promising. You should set this up in a cold but frost-free place such as the balcony or a shed, as it is a cold germinator acts. In the spring, when the first shoot can be seen, plant the walnut again in a new pot with soil. When the late frosts are over, the seedling can be placed in its intended place and should be watered regularly.

It is also possible to buy plants that have already been grafted in specialist shops. Yields are often safer and more predictable here because the characteristics of the plants used are known. Grafted walnut trees can also bear fruit as early as four or five years, while seedlings take 10 years or more to bear fruit.

Another option is to propagate ungrafted walnut trees by piling up. To do this, a young plant should be cut off about a hand’s breadth above the ground and earth should be “heaped” over the stump. In the best case, many new small shoots form. If these are rooted, they can be cut off or torn down and replanted in the ground.

It is also important to know when choosing a location that non-grafted seedlings often grow later in width and grafted walnut trees tend to grow taller.

Tip: It is also possible to refine the walnut tree yourself, but it is a bit more demanding and can only be achieved with a little background knowledge and the right technical equipment.

felling walnut tree

If you want to cut down your walnut tree, you should first find out about the applicable regulations from your municipality. In most regions, it is illegal to fell walnut trees by trunk size without a permit. In addition, according to the Federal Nature Conservation Act, a tree felling on private property between 1. March and 30. September not allowed. If this permit has been granted and you are new to felling large trees, it is best to hire a professional.

Harvesting and using walnuts

Around September it is harvest time for the walnut tree. When the fruit is ripe, the green skin peels off and the familiar brown walnut emerges. This is strongly brown in colour, which is why gloves and non-sensitive clothing are best suited for collecting.

Due to its many nutrients, the walnut is a true superfood. It contains a relatively large amount of zinc, potassium, calcium, vitamin C and nutritionally valuable unsaturated fatty acids. It can be used directly, for baking or as a fine flavor supplement when cooking. Walnut ice cream is also finding more and more friends. Nuts are also a popular food especially during the Christmas season.

Pests and diseases of the walnut tree

A common pest on walnut trees is the walnut fruit fly, which was relatively recently discovered in Europe (Rhagoletis completa). This bites into the green shell to lay eggs. The maggots then eat the flesh, which turns black. The nut itself remains intact except for a few black spots on the shell.

A common disease on walnut trees is leaf spot disease, which occurs shortly after flowering, especially in very humid weather. This can be caused by various bacterial or fungal pathogens. A severe infestation can mean that the nuts are no longer edible and that the tree sheds all of its foliage before the fruit is ripe. Some varieties such as 'Sheinovo' or 'Reinuss Kläusler' have resistance or increased tolerance to some leaf spot diseases.

Are parts of the walnut tree poisonous?

Parts of the walnut tree can be toxic to animals such as horses.
Plant parts such as leaves are also harmless to humans, but these or the green peel can lead to gastrointestinal problems or severe vomiting in sensitive people.

The walnut is considered a superfood - this is partly due to its high zinc content. You can find out more in our special article Fruits and vegetables high in zinc.