Vitality:
Weakened plants are more often affected by diseases or pests. The first important measure of preventive plant protection is therefore to provide the plant with an optimum supply of light, warmth, water and nutrients. If one of these factors is too much or too little, this can already lead to a weakening of the plant. At this stage, pest infestation or disease can quickly occur.
Cleaning:
By carefully cleaning the plant, many pests can be removed at an early stage and the infestation in spring is significantly reduced. The bonsai can be freed from larval stages, pest eggs (see picture) and fungal spores using a brush or a low-pressure cleaner. Removing old leaves is also important and reduces the infestation of fungal diseases in spring.
Shoot spraying:
Winter or budding spraying has proven its worth before new shoots appear. This involves spraying the bonsai with an oil-based pesticide. Make sure that the plant is completely wetted with the product. The oil film surrounds both active animals and their hibernation stages and leads to the death of the pests through exclusion of air.
Aphids:
In spring, the plants begin to sprout tenderly and the aphids are not long in coming. They are particularly keen on fan maples and coneflowers. The fresh shoots are particularly sensitive to the sucking insects. The sooner you remove them, the better. Rinsing with water is often enough. Otherwise, natural remedies such as potash soap, Neudosan Aphid Free or Spruzit have proved effective.
Powdery mildew and leaf spot:
To protect leaves from fungal diseases such as mildew and rust, early and regular use of preventive agents such as Armisan or net sulphur is recommended. Strengthening the plant with products such as Neudo-Vital is also beneficial here. If the plant does become diseased, a systemic agent such as Fungisan can be used.