Thujas are plants that are very eagerly planted in gardens. Unfortunately, along with the growing popularity of these plants, more and more oftentui diseasesThese can be bothtui physiological diseases(resulting from improper growing conditions or inadequate care plants) andfungal diseases of tui(caused by an attack by pathogenic fungi). The most frequently observed symptom of thuja disease isbrowning of thuja needlesSee how to recognize thuja disease andhow to fight thuja diseaseso that plants regain their beautiful appearance quickly!
Thuja - fungal diseases, browning of thuja needles
In the photo shoot dieback of coniferous trees and shrubs. Thuja scales turn yellow,
starting from the top, then turning brown and dying off.
Physiological diseases tui
When you notice disturbing symptoms on your thujas, , such as a slight browning of individual twigs, do not panic right away. First of all, you should pay attention to specific symptoms, the time they appeared and the weather. Many symptoms are not infectious because the cause of their appearance is physiological. We are then talking aboutphysiological diseases of tuiWe can counteract them by improving the growing conditions of the plant.
Autumn browning of thuja
A good example of this isbrowning of thuja needles occurring in autumnIn autumn, the upper side of the scales turns brown, and in spring it turns green again.It is a completely natural physiological process of thuja in preparation for wintering and should not be particularly worried about. It is not a disease of any kind. This symptom is seen in many popular thuja varieties, including the fast-growing hedge variety Brabant. However, there is no tendency to brown needles in winter, however, another popular variety of thuja planted in hedges - Emerald thuja.
Drying of thuja during winter
It is also common tobrowning the needles of tuiin the winter. Then it is suspected that the plants have frozen. Meanwhile, thuja is a highly frost-resistant plant, while as an evergreen plant it needs water for vegetation all year round, also in winter. During this timethe thuja shoots are dried by the frosty dry winds , and the plant cannot take up the missing water from the frozen soil and it withers. Therefore, the thuja should be watered abundantly in the fall, before the onset of frosts, and if necessary, the plants should be watered in winter, during periods of thaw, when the soil is thawing.It is also advisable to mulch the soil under the thujas, which reduces water evaporation and helps to keep the soil constantly moist. Pine bark works great as a mulch under the throne, which should be spread with a layer of 5-10 cm. Plant screens or other covers will also help to protect the thuja from the chilling, drying wind.
Dog or cat urine damage to thuja
If we have pets (a dog or a cat) that will urinate on our thuja, we can be sure that the scales will also start to discolor and die.If the scales on the lower stems of the thuja turn black and shiny, this indicates damage from the animal's urineThe only way to prevent this is to surround the plants with a net to prevent the animal from reaching the plant . For more information on how to discourage your dog from urinating on plants, see the dog in the garden article.
Improper fertilization of tui
Incorrect watering or applying fertilizers in too high a concentration can also lead toburns and browning of the thuja needlesEspecially if the mass browning of the thuja shoots is progressing very quickly. In the event of disease or other cause, the browning of the shoots will usually be much slower. So if yourturns brown quickly, dying off in just a few days , think about overdosing your fertilizer. A possible salvation can bewatering thuja abundantly in order to flush as much fertilizerinto the deeper layers of the earth. Of course, we also stop fertilizing until the situation stabilizes.
Fungus diseases of tui
Tui phytophthora
Phytophthorosis is a common thuja fungal diseaseIts symptoms most often appear in the second half of June. The result is yellowing, browning and dying off of the plant. Thuja is also stunted and the wood turns brown at the base of the stem.
How to combat this thuja disease?Unfortunately, strongly infected plants should be removed, and those with initial symptoms of the disease and all growing nearby should be sprayed and watered with the biological preparation Polyversum WP. If we cannot purchase Polyversum WP, the plants can be watered with Proplant 722 SL or Magnicur Energy fungicide.
Scorpion 325 SC can also be used to spray thuja suspected of being infected with phytophthora . As for the latter preparation, the registration of Scorpion 325 SC was extended in 2019, which allows itto be used on thujas against phytophthorosis
To protect against phytophthorosis newly planted thujas , before planting, it is worth adding an admixture of composted pine bark to the substrate, which inhibits the development of the pathogen. As a preventive measure, mycorrhiza also helps, which improves the overall condition of the plants. The SYMBIVIT® preparation works perfectly as a mycorrhiza for thuja.Mycorrhizal fungi useful for plants strengthen the overall thymus, help them take up nutrients from the soil and reduce the growth of pathogens.
Thuja root rot
Thuja root rot isanother mushroom diseaseThuja scales become dull, turn yellow and brown. Large patches of white mycelium appear on the surface of the bark and on the wood itself. The bark at the base of the shoots turns brown, dies and cracks, revealing the wood.
Thuja attacked by armillaria must be removed absolutelyIn the past, it was also recommended to water the thuja growing nearby with the fungicide Rovral Flo 255 SC. Currently, however, this remedy is no longer available. All that is left is to strengthen he althy plants by proper care, fertilization, the use of mycorrhizal vaccines and spraying with the natural preparation Biosept Active.
Since the mycelium of Hymenoptera can survive in the ground for many years,it is not recommended to plant a new thuja , in place of the removed plant For new plantings, choose plants that are resistant to Hymenoptera attacks.
Shoot dieback of coniferous trees and shrubs
Another frequently observed disease in thujas isshoot dieback of coniferous trees and shrubsW in this case, necrosis of the shoot base, dieback of scales and cankers appear. The thuja scales turn yellow from the top, then turn brown and die. In such a case, the infested parts of plants should be cut out and removed from the garden and optimal conditions for the development of thuja should be ensured. Thuja must also be sprayed with Topsin M 500 SC (0.1%) fungicide.
Gray mold of thujaGray mold may also be present on thujas. It appears on thujas grown under poor conditions. Water-soaked spots appear on the scales, which then turn brown and die. If it is wet, a gray mold bloom appears on the disease spots. Infested parts of plants should be removed, and thuja growing as a hedge should be kept so that they are not too thickened.Thuja infected with gray mold should be sprayed (once or twice) with the fungicide Magnicur One-Day 500 SC or Signum 33 WG. Natural preparations Biosept Active and Polyversum WP, which can be used for subsequent spraying in order to prevent disease recurrence, will also be helpful.
Fusariosis of tuiFusariosis of tui is caused by fungi. Initially, it affects only the tops of the shoots, but quickly moves to the scales, which turn yellow, then turn brown and die. In the final phase, orange spore clusters can be seen on the necrotic spots. Plants infected with fusariosis should be cut and removed, and the adjacent thujas should be sprayed several times with Topsin M 500 SC (0.1% concentration).
The agents for combating thuja diseases mentioned in the article can be ordered in the shop of our guide. To see the list of available preparations, press the button below.
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Note!
Until recently, it was common practice to burn plant debris infested with diseases and pests to prevent the spread of pathogens. However, according to current regulations, smoking leaves and branches, even if they come from diseased plants, is forbidden. From gardens and plots, we should dispose of them in accordance with the principles of segregation and waste return in force in our commune. Cut branches and removed leaves are called green waste.
