Help the development of the site, sharing the article with friends!
The Japanese maple Acer Palmatum, also known as the Japanese maple, originally from Asia, is a popular ornamental tree not only in Japanese gardens thanks to its filigree and intensively colored foliage. It can be cultivated in beds as well as in tubs and becomes more and more magnificent from year to year. However, this exotic tree is quite demanding and, under unfavorable conditions, can be attacked by diseases that manifest themselves in leaf damage, among other things.
root cause
When leaves curl, curl or turn brown
Leaves that are turning brown, curling up or curling, as well as leaf fall in summer and whole dry shoots or branches, usually indicate the wilt disease there. Even if the Japanese maple Acer palmatum is generally robust and relatively easy to care for, it is still demanding when it comes to site conditions. If they are not optimal, it can promote fungal infestation. This fungal disease can be deadly for the magnificent Japanese maple. It is all the more important to observe the requirements of this ornamental tree and to implement them as best as possible.
wilt disease
What constitutes wilt disease?
- Verticillium wilt primarily affects maples
- Transmitted by Verticillium alboatrum and Verticillium dahliae
- Soil-borne fungi that can survive in the soil for up to 15 years
- Wilt disease is dangerous and highly contagious
- Advanced infestation is usually fatal for the affected plant
- Plants with already weakened root systems are particularly susceptible
- Fungus enters through bark or root injuries
- Gets into the pathways of individual branches or shoots and grows
- Distributed throughout the plant by the water flow
The Japanese maple tries to ward off this fungus by so-called Thyllen (filling cells, protuberances). As a result, the pathways become clogged, the water supply to individual sections of the branch comes to a standstill, and they become dry and die.
Favorable Factors
The wilt disease is favored by unfavorable site conditions, soil compaction and impairments in the water supply. If the location is rather unfavorable or the care does not meet the natural needs of these plants, this makes them much more susceptible to this fungus. Especially years with strong heat and drought as well as a location in direct sun can promote this fungus.
In addition to drought, too much moisture can also promote an infestation. The Acer palmatum Japanese maple needs evenly moist soil, but it is very sensitive to standing water. Ideally, the top layer of soil should be allowed to dry before each new watering.
tip: In the case of potted plants, water should never be allowed to stand in saucers or outer pots.
detect infestation
- Initially, the bark of affected shoots becomes slightly wrinkled and dries up
- Leaves on these shoots turn brown, dry up, hang limply
- Often mistaken for sunburn
- Shoot buds also turn brown
- Later the entire drive dies off
- Cross-section of a dead branch can clearly determine or rule out an infestation
- Affected branch shows brownish-black, often ring-shaped discoloration in the pathways
- With advanced infestation, more and more shoots and branches become dry
- Plants, especially younger specimens, die off
- Combat only possible to a limited extent
Verticillium in branch cut
combat
A direct control of Verticillium wilt is with spraying or watering agents not possible. There is currently no fungicide on the market that can effectively combat this fungal disease.
If the infestation is not yet advanced, you can try to save the plant by cutting out infected parts of the plant.
It is important to cut down to the healthy wood and not to dispose of the clippings in the compost, but only in the household waste. Fallen leaves must also be completely removed from the ground. Cuts are then best closed with a fungicidal tree wax. As long as the plant has not yet completely died, you can fertilize it with a shrub or hedge fertilizer after cutting and thus stimulate it to sprout again.
tip: Pruning tools should be sharp to avoid crushing shoots and branches and be sure to disinfect after cutting. This is to prevent the fungus from spreading to other plants.
prevention
- Prevent wilt disease with the right planting
- Do not injure roots when planting
- Dig the planting pit deep enough and fill it with loose substrate
- Loose soil should prevent waterlogging
- The introduction of a drainage layer approx. five centimeters high is recommended
- If possible, plant maple a little higher up so that excess water can run off
- In case of repeated infestation, remove the plant completely
- Don't plant a maple in the same spot again
- Ensure an optimal supply of water and nutrients
- Avoid one-sided fertilization, especially one that is too nitrogenous
Maples should never be planted in a location where this wilt disease has already occurred. Not even if the floor was generously replaced afterwards. The best thing to do is to only plant trees that are as resistant as possible in this place.
tip: Depending on the nature of the soil, lowering the pH value can also minimize the risk of infection.
Other causes
Leaf tip and leaf edge drought
If the leaves turn brown and dry up, this can also be an indication of leaf tip drought being. This occurs above all when the Japanese maple Acer palmatum is in a draughty or too windy location. On the other hand, brown spots on the leaves, especially in sunny locations, indicate burns. Therefore, when choosing the location, you should look for a partially shaded and wind-protected spot.
If the leaves curl or curl, this can be due to the so-called leaf edge dryness indicate. Because in contrast to wilt disease, no complete parts of the branches die off in leaf edge drought and the plants sprout normally again the next year. This problem also occurs in sunny, unprotected locations in connection with unfavorable soil conditions