Root and stem rots are caused by different kinds of pathogenic fungi due to excessively humid environments. The symptoms can be noticed by dark spots in progressive extension and wilting of the whole plant.
Herbs are generally the least susceptible to pests thanks to the high content of essential oils. However, it is useful to know how to intervene with natural remedies in case damages occur.
Aromatic plant threat: pests
Insects 1-2 mm long, green, yellow or black that nest on the tips of the plants. They can be removed by hand (using gloves) or, if numerous, a product based on natural pyrethrum can be used when and where it is really necessary.
Classic green or brown bugs with a pentagonal shape. They bite and suck plant tissues, but the major nuisance is given by the unpleasant smell. To rid the plant of these bugs, it is sufficient to shake the plant when harvested.
Small whitish insects that stick to the trunk and branches of some herbs. If they are a few, just remove them with a paper towel soaked in water and alcohol. Otherwise you need to treat them with specific mineral products.
There are numerous species that chew leaves, buds and stems. When they are present in large colonies, deal them using natural pyrethrum.
Diptera that lay eggs within the plant tissues, feeding of the bearing larvae. An efficient weapon is pairing affected plants with other plants whose smell is unpleasant to the fly. For example, plant carrots among garlic and onion plants and you’ll find that the flies attracted typically to those plants will be dissuaded.
Mites belong to the group of arachnids, invisible to the naked eye. The leaves appear faded in spots and thin webs between them are visible. Reduce mites by increasing the humidity of the soil and of the surrounding air.
Aromatic plant threat: fungi
Root and stem rots are caused by different kinds of pathogenic fungi due to excessively humid environments. The symptoms can be noticed by dark spots in progressive extension and wilting of the whole plant. The affected plants must be entirely eliminated, together with the soil.
This plant invader is manifested by a powdery white layer that covers the leaves, which then fall off (it is common on sage plants). It is abundant in mild and damp climates but it is possible to control its development by spraying sulphur.
Fungi that causes root rot in young herbaceous plant species which suddenly wither. Remove the plant and soil entirely.
These are diseases that are evident in the form of small brown or reddish pustules on the leaves. They should be treated with copper salts but if the infestation is aggressive, plant eradication and the elimination of soil are more effective.
This fungus penetrates small superficial wounds. Brown spots appear on the leaves and the plant wilts. Treat with copper if the infection is contained, otherwise renew your cultivation with healthy specimens.