Problems in the cultivation of thuja most often result from improper care of these plants or an attack of a fungal disease.Pests on thujaappear much less frequently. The most dangerous of them isTujowiec swordfish , which can destroy the entire plant. Sometimes an aphid appears on thuja -Cypress honey plantSee how to recognize these pests and how to combat them.
Pests on thuja - Tujowiec cupola
Fig. © PoradnikOgrodniczy.pl
Tujowiec cupcake
Cuplets are the most commonpests on thujaUsually, attacksof the thuja cup(Parthenolecanium fletcheri) are affected by the Western Thuja, especially the varieties with thickened shoots, such as thuja 'Danica' or 'Hoseri'. They are popular spherical thuja and therefore I recommend that you carefully inspect the shoots of all spherical thuja in our gardens from June. Deflect the shoots and check them carefully forsymptoms of thuja cup feeding
In spring, female bowls feed on thujas, and in summer - their larvaeWe can then observe trardes, spherical bodies of a bowl, which may be brown or brown-red on the shoots. They are small, usually 1-3 mm, but we can see them quite easily. Especially if we bend the twigs and look under them from the bottom and inside the bush's crown.As a result of feeding the cup on thujasshoots die and the scales are covered with honey dew secreted by the pest.Over time, the sticky discharge becomes covered with black fungus, which makes the thuja shoots very unsightly. Even if we do not see the pests themselves, the black sticky coating on the thuja twigs proves their presence.The same symptoms can also be observed on yews, which are attacked by the yew tree. It is a pest that is very similar to the thuja moth, but has different preferences for the plant species it attacks. Both the yew cup and the thuja cup are fought in the same way.
Pests on thuja - Tujowiec cupola
Fig. © PoradnikOgrodniczy.pl
The thujowiec cup can be foughtduring the hatching and feeding period, that is from June to September. For spraying, insecticides are used, such as: Karate Gold, Mospilan 20 SP, Polysect 005 SL.
If we do not have a garden sprayer or do not want to prepare the spraying liquid on our own, it is worth knowing that there are alsopreparations for the thuja cupready to use, sold in containers with a sprayer.Perfect for spraying individual small plants on balconies and terraces. They are: Karate Spray and Sanium AL.
Above all, however, the protective treatment should be performed in the early spring in order todestroy the wintering forms of the thuja cupThis will prevent it from reappearing in the summer. For this purpose, oil preparations approved for organic farming are used: Promanal 60 EC and Emulpar 940 EC. The use of these agents in the early spring does not cause any harm to the environment, unlike the insecticide spraying performed during the growing season.
The Emulpar 940 EC mentioned here can also be used from spring to autumn, after noticing the larvae of the thuja cup. It is also available in a ready-to-use version in a spray canister called Emulpar Spray.
Aphid - cypress honey plant
Aphids can also feed on thuja, and the most common isCypress honey plant(Cinara thujophylline).According to the literature, this aphid mainly attacks the thuja. However, I have seen aphids on Western thuja many times, including the popular hedge variety, which is undoubtedly the Brabant thuja.
In the case of an aphid on thuja shootsyou can see clusters of wingless or winged insects , sucking the juices out of the plant and covering its shoots with a sticky discharge. As a result of their feedingthe thuja shoots may turn brown and dry up
To combat the thuja aphidswe can use the same preparations as mentioned above on thuja bowl. Sometimes a regular potassium soap with a garlic scent is also enough to scare away aphids.
