Kugelrobinie, Kugelacacia – plants, care, cutting & diseases

When planting the Kugelrobinie, it must be taken into account that the plant as a whole can occupy a considerable overall height; the plant also grows greatly in width. For this reason, an area in the garden should be chosen that offers a lot of space. Basically, warm locations are suitable, but the plant does not have any problems even with intense sunlight. In addition, the plant can generally tolerate drought and urban climates very well. However, the branches of the spherical curve show a certain sensitivity; in heavily blowing locations these tend to bend. In order to protect the delicate branches, a location protected from the wind should therefore be chosen. If children live in the house, areas in the garden should be chosen that are not accessible to them. Due to the toxicity of the plant, adequate protection is essential here. In principle, keeping them in the bucket is also possible. On the balcony or terrace, the spherical line feels particularly comfortable in locations in partial shade.

In order for the plant to thrive optimally, the use of a suitable substrate plays a role. The soil should have certain characteristics:

• rich in nutrients
• loose texture
• permeable to moisture
• somewhat calcareous

Ball acacias thrive when the soil contains only a small amount of lime. If the substrate used is very calcareous, the plant no longer feels good. Particularly heavy and impermeable soils are also unsuitable. A clay soil is ideal for cultivation; however, dry soils, for example gravel or sandy soils, can also be used.

Care of the ball acacia

The ball acacia is very robust and easy to care for. Plants that are in the garden are only watered regularly when they are being grown. If the plant has grown into a young plant, the tree is self-sufficient. This also applies to the nutrients; the use of an additional fertilizer is usually not necessary because the spherical curve pulls the required substances out of the soil itself. Cultivated in a tub or in a pot, however, the plant must be watered regularly during the summer months. In winter, the plant is only watered very sparingly. You just have to make sure that the plant does not dry out completely.

Due to its robustness and undemanding nature, the plant grows easily in the garden without the need for additional care. However, the vigor often leads to the displacement of other plants. In the long term, the plant can also contribute to a change in soil conditions.

Optimally overwinter

Kugelrobinien overwinter in the garden without any problems. If the plant is cultivated in a tub or pot, it should be moved to a cold house during the winter months. Here the plant hibernates in a dark place at temperatures around 0 ° C. Under no circumstances should the acacia hibernate in a warm room; in this case the plant reacts quickly by shedding the leaves.

However, the globular robinias cultivated in the tub can also remain outdoors during the winter months. However, in this case the plant should be moved to an area protected from the wind. Additional protection against frost is also recommended; for this purpose, the planter can be covered with coniferous twigs, straw or wood wool. Alternatively, the bucket can also be placed in a larger container. The space between the two containers is then filled with insulating material that contains air pores.

Carry out the maintenance cut correctly

There are different options available for intersecting the spherical line:

• Thinning out the entire tree
• Shorten the crown
• Radical cutback

In the ideal case, the spherical line is only thinned out. For this purpose, branches and smaller twigs that show damage are either cut off with plant scissors or cut off with a hand saw. When cutting, it is essential to use a clean technique and work directly at the base so that no stub remains on the trunk. If large wound areas arise during cutting, treatment with a special wound closure agent is recommended. Sometimes it has also proven useful to remove healthy branches, for example for decorative reasons; If the branches of the crown are evenly distributed, the result is a symmetrical picture.

Especially in the case of spherical acacias, which are in a poorly protected area of ​​the garden, often suffer damage in the crown area, which is caused by strong winds. In this case it has proven to be useful in many cases to shorten the entire crown. In this way, the uniform shape can be obtained. In the ideal case, the branches are shortened to about 2/3, more often it may be necessary to shorten them. However, there is a risk that branches that are already large in size will knock out very strongly after they have been cut. In this case, the excess shoots are removed so that the natural crown shape can develop again and the spherical acacia grows again spherically.

Hobby gardeners should only resort to radical pruning in an emergency. This can be the case if there is very strong wind and weather damage to the entire tree. Then the crown should be cut radically.

A little head should remain above the finishing point after the radical cut. In the case of radically cut plants, shoots that are too close together must be removed regularly at the beginning so that the classic spherical shape can develop again.In addition to the right technique, the ideal cutting time should also be considered:

• The winter months are suitable for every cut.
• The cut before the start of budding shortens the time of the mutilated optics.
• Damaged branches are cut off immediately all year round.
• Under no circumstances should a cut be made during the budding period.

Propagation and planting

The ball acacia is propagated through grafting. Here shoots of small-crowned types are grafted onto common robinia. This measure ensures that the trunk only grows in width, but not in height, while only the crown changes its size and gradually develops into a spherical shape.
Ball acacias can be planted all year round, provided the plants are offered in a potted container. On the other hand, if the specimens are bare-rooted, the period between September and April has proven to be particularly useful. Root crops, which are available in autumn without bales, are also planted in winter. However, plants can only be planted if the soil is frost-free. Before the spherical acacia can be brought into the ground, the soil must be prepared accordingly. For this purpose, heavily compacted soils are loosened. Then a plant hole is dug, which must be large enough for the roots of the plant to develop optimally. The spherical line is planted in the hole so that the base of the trunk is above the ground. So that the plant stands securely until roots are formed, a stake should be placed next to the trunk, to which the plant is fixed. At the beginning of the cultivation the ball acacia is always well watered; adult plants are self-sufficient.

Pests and diseases

The ball acacia is attacked by different pests. Leaf miners appear particularly frequently, which can be recognized by a very typical damage pattern; the moths eat their way through the leaves as early as spring and leave behind characteristic feeding tunnels on their way, which are drawn in serpentine lines on the leaf. The caterpillar itself is at the wider end of the feeding passage. There it can be crushed directly as an immediate measure. In general, however, no targeted control of the leaf miner is necessary, as the Kugelrobinie usually can deal with the pests itself.

The situation is completely different with various lice that regularly infest the spherical acacia. This is mainly the aphid. After the infestation, the leaves turn yellow and tend to shed prematurely. Various options are available for effective control:

• Spray the affected parts of the plant with water
• Spreading lacewings and gall mites as natural enemies
• Use of attractants such as nasturtiums
• Soap solution sprayings
• Use of herbal extracts such as tansy tea and nettle extract
• insecticides

The ball acacia is also attacked by scale insects; the characteristic shields of the lid or bowl-shaped lice are easy to see on the leaves. The pests suck the sap from the leaves, which can damage the plant. Natural enemies can be used as a preventive measure. These include, above all, ladybugs, parasitic wasps and earwigs. In acute cases it has proven to be useful to brush the shields off affected branches and shoots; this works best with the help of a toothbrush. The use of different oily sprayings has also proven itself. In this context, preparations based on paraffin oil or rapeseed oil are of particular importance. The oil covers the lice like a film and suffocates the pests.

In addition to various pests, the ball acacia is also affected by certain diseases. Phloespora leaf spot disease occurs particularly frequently. This pathogen, which can be traced back to a fungus, causes the leaves to wither. At the same time, the disease causes a characteristic leaf markings that also consist of brown circular spots. Infested leaves should be removed in autumn. Often the shoots are also affected. Then the entire crown has to be cut back. Even care errors can be responsible for a disease of the Kugelrobinie. Wilted leaves or stagnant plant growth are often the consequences of a loamy substrate or waterlogging.

Toxicity

Almost all plant parts of the Kugelrobinie are poisonous. For this reason, children should be kept away from the tree. The plant contains certain ingredients that are counted among the lectins; particularly high concentrations are found in the bark, while leaves and seeds contain only small amounts of the poison. The flowers are completely poison-free.
According to the literature, the first signs of disease can be expected from a quantity of around five seeds. These are mainly symptoms such as nausea, nausea and abdominal pain. An accelerated heart rate can also occur. In addition, the poisoning often manifests itself through collaptic conditions, in which seizures can occur. In animals, the consumption of the plant parts can lead to death.

The first measure against poisoning is a high intake of fluids. From an ingested quantity of about five seeds, the poison is removed as part of a medical treatment, which is accompanied by the administration of medicinal charcoal.

Conclusion
The unpretentiousness of the spherical acacia makes the majestic plant a popular garden plant that every hobby gardener, from beginners to advanced gardeners, can cultivate. However, due to its toxicity, care should be taken when handling the plant. Well cared for and cut if necessary, the spherical acacia always retains its typical spherical shape and thus provides a decorative element in the home garden.