Nearly all leaves fly around the planted rowan sometime in June, there are no berries either (2-3 brushes), in September new leaves bloom, bright green. The tree is already about 4 meters.
Depending on the characteristics of pathogens, signs of leaf damage appear in May-June or in the second half of summer. With the massive spread of diseases with a severe degree of damage to leaf blades, premature drying and falling of leaves is observed. You did not describe exactly how the leaves dried out, the exact diagnosis of the disease depends on this. And this disease, undoubtedly, therefore I can’t say what kind of fungus the mountain ash suffers. But the treatment for such diseases is similar and includes the following measures:
- Watch the emergence and spread of the disease from May to September.
- Create comfortable conditions for the growth and development of mountain ash, increasing its resistance to diseases.
- Cut the diseased and shrunken branches in the summer, and in the autumn collect all the fallen leaves - burn.
- Spray in May-June, also at the end of August, with fungicides approved for the protection of woody plants.
- Dig the soil onto the bayonet of a shovel in late autumn or early spring around the trunk.
Folk remedies in the fight against fungi and their pathogens are not effective or give a temporary effect. One of the reasons for not bearing the mountain ash is if the branches grow very steeply upwards (more than 45 degrees). Give the branches a more horizontal position in different ways, for example by hanging a sinker or bending the rope to the ground. Horizontally growing branches will certainly bloom.