Wrong care can make the otherwise robust bonsai susceptible to diseases and pests. Read here how you can save your plant.
You always keep an eye on your bonsai progeny. They simply need special care so that they can develop magnificently. However, the regular assessment also has its positive side. Symptoms of illness are recognized quickly and you can intervene accordingly.
The most common maintenance mistakes are in the water supply. Small errors can be recognized immediately with the blade diagnosis:
Your bonsai suddenly gets yellow, withered or dry leaves that eventually fall off? Then he clearly gets too little water. On the other hand, if the leaves gradually turn yellow and die off, too much water, too much fertilizer or a lack of nutrients are to blame.
» Reading tip: Fertilize bonsai - this is how the plant gets all the important nutrients
Viral and fungal diseases in bonsai trees
Bonsai can catch a virus or get sick with a fungus. You can recognize the disease by the pale, yellowish leaves or needles. The branches die off. Quarantine and hygiene are the first measures. The triggers are often transmitted by touch, which is why handling them as separately and cleanly as possible is extremely important.
Remove the infected parts and separate the affected plant. Fungi can usually be fought well with a fungicide (my recommendation: bestseller no. 1 Compo Duaxo Universal Pilz-Frei) as long as the disease has not yet taken hold of the entire bonsai.
➜ Stem Rot and Root Rot
Recognize:
Root rot and stem rot are caused by bacteria and fungi, respectively. The stem rot destroys the bonsai from the inside. The trunk and branches turn reddish-brown from the inside. The disease mainly affects yew, walnut, horse chestnut, pine, box and olive. Waterlogging and poor air exchange promote stem rot.
Root rot occurs on the root ball and destroys the bonsai from below. Brown, wilted leaves and a foul smell are usually the first signs. The roots become soft and mushy, the water transportno longer works. Again, waterlogging is a factor affecting root rot. So always think of good drainage and carefully regulate the water balance of the bonsai!
Fight:
It is often generally advised to completely dispose of bonsai trees affected by stem or root rot. But you can also generously remove affected parts. Then place the bonsai in fresh substrate and be sure to keep it separate until you are sure that it has recovered well. Fungicides (see above) are effective against fungi that cause root and stem rot.
If all else fails: remember not only to remove the bonsai, but also to clean the planting tray thoroughly, preferably with alcohol.
➜ Fire hazard: fire blight on bonsai
Fire blight is caused by bacteria. The leaves turn brown to black and the tree dies. There is no antidote, unfortunately the bonsai must be destroyed.
Pests on Bonsai Trees
➜ Aphids:
Aphids often spread on the bonsai. Bathe the bonsai upside down in a mixture of detergent and water, preferably repeat several times.
➜ Scale Insects:
Scale insects also damage the bonsai. Reach for a biological spray based on paraffin oil, such as the sprouting spray from Bayer.
➜ Blood Louse:
The blood louse is the most dangerous type of louse. It sucks on the woody parts and causes malignant boils. Here, too, you can use the biological spray just mentioned.
➜ Apple Tree Spider Moth:
The apple tree spider moth is another well-known bonsai pest. It is a moth that lays its eggs on the shoots. The hatched caterpillars eat the bonsai completely bare in a very short time. Visually, the infestation is shown by a grey-white web between the leaves. You can try to scrape the eggs and collect the caterpillars. Again, place the bonsai separately so that the pests don't spread to other plants.