7 Recognize and combat diseases in thuja hedges

Arborvitae are among the most popular hedge plants and can be found in numerous gardens throughout Central Europe. Their wonderful green tone and the dense growth are the reason for the popularity of the plant, which is actually from North America and East Asia and established themselves in Europe for their appearance and usefulness. Thuja hedges rarely suffer from disease because they are very robust. If problems arise, you need to identify and deal with them quickly.

Diseases of thuja hedges

In Germany, trees of life are mostly kept as a hedge, which is attractively presented in the garden or separates the property from the neighbors as a privacy screen. The cypress family (bot. Cupressaceae) are very robust plants that get by with little care and inspire with their fresh green. Healthy thuja can be recognized by the following properties:

• lush green color of the leaf scales
• young leaf scales also green
• strong growth
• upright shoots

If the crop is not doing well, this is immediately noticeable, as the scales in almost all thuja hedge diseases discolour brownish. There are a total of ten diseases that can result from fungi and care errors. It is important to identify and combat these as early as possible so you don't lose your hedge. Fungal diseases in particular are fatal in thuja hedges, as the spores can easily pass from one plant to the next. If you suspect a disease, check the conditions below and use treatments to save your hedges.

Cause: maintenance error

In many cases, carelessness errors are the more common cause of thuja hedge diseases. Fungal infections follow this very often, but are not always related to it. One advantage of care errors is the ability to deal with them quickly with the right measures. Three typical care mistakes have a particularly strong effect on the plants. You will learn how to handle these in the following sections.

tip: The gradual brown coloration of the scale leaves in autumn, which persists through winter and is slow but continuous in certain species and varieties, is not a care mistake. These include the occidental tree of life (bot. Thuja occidentalis) with the varieties' Brabant ',' Holmstrup 'and' Columna, as well as the giant tree of life (bot. Thuja plicata), which take on a shade of brown reminiscent of bronze in various intensities.

Waterlogging

Waterlogging leads to stem and root rot in arborvitae, which can be fatal for the plant. Since this is a slow process, it is usually not immediately visible and sometimes even only when it is too late. The reason for this is the fact that the scales do not turn brown from waterlogging, as is the case with other diseases. Therefore, it is hardly noticeable when your tree of life has been submerged. Arborvitae generally prefer slightly more humid soil, but the roots must not be permanently wet. If the waterlogging has got out of hand, the rot is shown by the following symptoms:

• Plant is weak
• soft parts of plants
• white coating on the trunk
• white coating on roots
• wet earth

If this has been the case for a very long time, the symptoms of weakness and rot cause the plant to perish. For this reason, once you discover the waterlogging or rot, you need to act as soon as possible so that you don't have to dispose of the entire plant. First check the roots and remove most of the infected parts of the plant. Freshen up the location of the arborvitae hedges with dry soil to remove some of the moisture and remove possible pathogens. If the rot has reached the trunk, the tree of life can unfortunately no longer be saved and must be disposed of. If this happens to you, you shouldn't put the tree on top of the compost, but take it to the nearest collection point for green waste. Fungal spores could have accumulated on the weakened plant material, which could otherwise be blown away.

dryness

Just as a problem as waterlogging is drought for thuja hedges. A big advantage compared to rot, however, are the obvious symptoms that are typical of the plant:

• leaf scales slowly turning brown
• Plant is weak
• slowly wither away

In addition to the brown leaf scales, you should also check the location. If the substrate is very dry, you can use one Lack of water go out. Immediate action is important here, because even short periods of time lead to the death of the plants, on the contrary, to waterlogging. In return, the symptoms can be recognized quickly and so you can act much more effectively and do not only notice the damage when the plant can no longer be saved. If you notice a lack of water, proceed as follows:

• immediately water the site
• Keep an eye on the plant for the near future
• likewise the location
• Adjust water additions accordingly

Beware of drought stress, as this can be a problem even in winter. Especially longer periods of frost without snowfall can cause thuja hedges to dry up. In this case you should wait for frost-free days and water a little to avoid possible damage.

tip: Another cause of the brown coloration in thuja plants is the use of the plant as a toilet for dogs. The constituents of the urine cause the scales to turn brown, the underside of which is getting blacker and blacker and they will die if you do not set up a barrier around the plant to protect the animals from it keep away.

Excess salt

An excess of salt occurs in arborvitae mainly in winter and is through Road salt caused. The road salt has a toxic effect on the cypress family and can burn the shoot tips in the lower area of ​​the plant. In the worst case, the plant will perish if large amounts of salty spray water get to the site and penetrate the soil. Unfortunately only that helps Transplanting the thuja, which shouldn't be done in winter, or a protective barrier to keep the salt from getting to the plant. The following measures can also help in the short term:

• Rinse the plant thoroughly
• water

Water will wash the salt deeper into the ground, which can help.

Note: Similar to an excess of salt caused by road salt in winter, there is overfertilization with too much mineral fertilizer. In this case, reduce the amount or change the fertilizer so that it does not over-salt the soil.

Cause: fungal diseases

Fungal diseases have a stronger effect on the vitality of the plants and can cause lasting damage. Since these are diseases that are caused by Spurs can be transferred to other plants, these must be treated much faster than the care errors. In the worst case, entire hedges can be destroyed by the fungus. To avoid this fate, you need to know about the four typical fungal diseases of thuja hedges, which you can control with the tips below.

Honey fungus root rot

The honey fungus root rot is caused by the fungus Armillaria mellea and can be recognized by large fungal braids that are dipped in yellow color variations. For this reason, the mushroom is also called honey yellow honey mushroom. The mushrooms sprout directly from the bark. As soon as you notice the fungi on your thuja hedge, remove any infected specimens immediately to prevent them from spreading to the healthy specimens. Unfortunately, there are no measures against root rot that can destroy the tree of life within a short period of time.

Pestalotia shoot death

This thuja hedge disease is an infestation by Pestalotiopsis funerea and can be just as devastating as honey fungus root rot. The reason for this are the trees of life that are weakened by acidic soils and cannot defend themselves against the fungus. The following symptoms indicate the serious illness:

• The leaf scales begin to turn brown
• from the tip of the leaf to the middle of the leaf
• even shoots are attacked
• dark brown spots, the size of a pin, on shoots
• entire plant can be attacked

The important thing here is to increase the pH of the soil. This should be between 5.5 and 6.5, so slightly acidic, but not too acidic. Likewise, it must not be too high, otherwise the scales will turn yellow. First remove all parts of the plant and dispose of them in the household waste. Then the pH of the soil is increased, for example with lime. If the plant is too weak, you have to dispose of it together with the potting soil.

Kabatina instinct death

You also have to combat the Kabatina thujae fungus, which affects young leaves and turns them brown. These spread over all leaf scales and even the tips of the shoots. In addition, they form black spore bearingsthat are distributed over the entire plant. Over time, the shoots and scales die off. Here it helps to thoroughly remove the diseased parts of the plant and freshen up the soil. This should have the following properties:

• relaxed
• permeable
• nutritious

Usually the infestation is limited to the scales and not to the whole plant.

Dandruff tan

Dandruff tan and kabatina dieback are very similar in symptoms. The big difference in Didymascella thujina is the focus on the older leaf scales that present similar spots and even spore beds. After the older leaf scales have been attacked, it is the turn of the young shoots. Thanks to the similarity of the two thuja hedge diseases, you can proceed here in the same way as with the kabatina shoot death. The location in particular is extremely important for healing.