- Causes of leaf spot disease
- Control is usually only possible by cutting away large areas
- tips and tricks
If the lavender gets yellow leaves with more or less large brown to black spots, the plant is infected with the dreaded leaf spot disease. This is sometimes referred to as shotgun disease because the leaves can appear punctured.
Causes of leaf spot disease
Various fungi of the Septoria, Ascochyta or Alternaria genera cause this disease, which is characterized by yellowing of the leaves and reddish, brown or black spots. Like all fungal diseases, leaf spot disease spreads quickly and eventually leads to the death of the plant. Such fungi primarily attack weakened plants that are too moist, too narrow or in an unsuitable location. Fungal infestation of lavender is particularly common in cold and humid summers.
prevent fungal infestation
Because controlling a fungal disease is difficult, prevention is an important measure. That's why you should look at lavender
- too much moisture, especially waterlogging,
- too much planting
- planting on unsuitable (loamy or peaty) soil,
- an intensive fertilization in particular with - nitrogen
- wrong hibernation
- and lack of light (half-shady or shady location)
avoid. Incidentally, the fungi survive even severe winters because they simply hibernate or leave spores on the plant. They can then continue to work in the following year and let the lavender die.
Control is usually only possible by cutting away large areas
As soon as the leaves and sometimes the stalks of the lavender are infested, you should tackle the fungus with hedge clippers (€77.00). Cut the lavender vigorously back into the healthy and unaffected parts. However, you should avoid cutting back into the wood, as the plant then usually no longer sprout. The tool must then be carefully disinfected so that any remaining spores are killed. If you don't want to harvest the plant, you can also use a broad spectrum fungicide.
tips and tricks
If, on the other hand, the lavender turns brown and looks like it has dried up, the cause is usually root rot caused by waterlogging or incorrect watering.
IJA