Help the development of the site, sharing the article with friends!
Lilacs and summer lilacs beautify many a garden and are usually quite robust. Cultivated forms - i.e. lilacs - are an exception here. These are more sensitive to viruses, bacteria and fungi and can therefore become ill more quickly. If changes are found on the trunk, leaves or flowers of the lilac, this always indicates diseases or damage caused by parasites. We explain what it can be and what rescue options there are.
lilac diseases
bacterial diseases
Lilac disease - Pseudomonas syringae
Lilac disease is a bacterial disease that causes changes to both the leaves and the trunk. The symptoms are:
- Darkening and brown stripes on the bark
- Shoots rot, dry up or buckle
- brown to black discoloration of the shoots
- Leaves show light or dark discoloration that weeps
There is no corresponding pesticide against the bacterial lilac diseases. Affected shoots must be removed and destroyed. It is also important that the plant is strengthened. A blend during the winter should be avoided urgently. For prevention and during treatment, winter protection is still useful. Because the bacteria ensure that frost damage occurs more quickly.
viral diseases
Viral diseases rarely occur in cultivated species of lilacs and summer lilacs. Possible signs are:
- bright spots, lines, or rings
- growth disorders
- deformation of the leaves
Again, no specific means of saving the plant is available. Since the viruses can spread quickly and cause major damage, you should remove affected plants immediately and dispose of the plant remains in the trash or destroy them. Otherwise, contamination of surrounding plants must be expected.
fungal diseases
Compared to bacteria and viruses, fungi are relatively common on lilacs. However, they can also be treated relatively well and the plants can usually be saved quickly.
From
Ascochyta leaf spot disease
Signs of Ascochyta leaf spot disease are:
- light gray spots on the leaves with a gray border
- withering of the shoots
- the bark tears open on the twigs and branches
As a countermeasure, it is usually sufficient to thoroughly remove the affected plant sections.
Leaf smut - Heterosporium syringae
The surface of the leaves becomes velvety, gray-brown, and may have circular spots. As soon as the plant is trimmed accordingly and the shoots are destroyed, it usually recovers from the infestation.
Leaf spot disease - Septoria syringae
Yellow-brown discoloration and a weakened, diseased appearance indicate leaf spot disease. The plant must be thinned out and all affected shoots cut off.
Galena disease - Chondrostereum purpureum
When infested with this fungus, the leaves turn silvery-grey. Purple fruiting bodies can be found on the trunk. Since it is one of the more serious diseases, a strong pruning should be done quickly.
From E - V
Powdery mildew - Microsphaera syringae
A whitish reference indicates the infestation. It helps to strengthen the lilac with appropriate means and at the same time use a fungicide. This allows the disease to be eliminated quickly. In addition, you should remove and destroy the shoots to prevent further spread to other plants.
Powdery mildew on a willow
Lilac Blight - Gloeosporium syringae
Large, brownish spots on the leaves indicate this lilac disease. Removing the affected shoots helps here too. In addition, however, a cut should be made to clear it out.
Ascomycete - Phyllosticta syringae
The sac fungus is difficult to recognize because it causes various types of damage to the leaves, shoots and flowers and can therefore hardly be distinguished from other diseases. It is difficult, especially for laypeople, to clearly identify this disease.
Here too, however, diseased parts of the plant must be removed. That at least curbs the lilac disease. Strengthening the plant at the same time, for example with lecithin, can help it heal.
Verticillium albo atrum
Shoots, leaves and even the bark can discolour, wither and die. A strong pruning is again advisable, and you should also treat the cut surfaces with wound closure.
Verticillium in branch cut
The right blend
If the lilac is affected by disease, you should pay attention to the following points in order to carry out a correct pruning:
- Disinfect cutting tools after each cut
- use sharp blades
- cut into healthy wood
- Discard clippings and never compost
Prevent lilac diseases
In order to prevent diseases of the lilac and buddleia, you should consider the following points:
- select the appropriate type
- choose the right location
- create optimal culture conditions
- avoid excessive fertilization
Hardy species
In order to be confronted as little as possible with diseases on the lilac or summer lilac, you should take a close look at the purchase. Robust and resistant species such as the common lilac (bot. Syringa vulgaris) or comparatively original breeds of it are rarely if ever affected by diseases. On the other hand, lilac varieties and especially hybrids from Asian lilacs are very demanding and at the same time very susceptible.
The situation is more similar with the butterfly or summer lilac (bot. Buddleja). Original forms are usually hardy and resistant to pathogens. Breeds or hybrids, on the other hand, can quickly suffer from diseases and, in contrast to Syringa vulgaris, are then difficult to save.
Buddleia
strengthen plant
The risk of diseases is lower, the stronger the plant is. Another important preventive factor is therefore site selection and care. As long as these are adapted to the crop, you hardly have to expect any problems. However, if there are changes to the leaves, flowers or trunk, care and planting should be checked urgently and adjusted if necessary.
Experience has shown that some lilac diseases can be nipped in the bud in this way, or at least more difficult courses can be avoided. This also includes fertilizing the plants appropriately but not with an emphasis on nitrogen or excessively. Because too much nitrogenous fertilization can weaken the defenses of both summer lilac and Syringa vulgaris.