Diseases of geraniumscan destroy the effort put into caring for these beautiful flowers. As a result of the attack of pathogens , geraniums turn yellow and dry , lose flowers or leaves. These symptoms may indicate an attack of a fungal or bacterial disease, but sometimes they are simply the result of errors in plant care. Seewhy geraniums turn yellow and witherand what are the best ways tofight geranium disease !
Diseases of pelargonium. Why do geraniums turn yellow and wither?
How to prevent geranium diseases?
In order not to drag geranium diseasesto our garden or balcony, let's make sure that the newly purchased plants come from a reliable source. At the time of purchase, if possible, let's check if they are free from pests or signs of disease.
Geraniums are particularly harmfulis exposed to excessive amounts of moisture in the ground and air, which promotes the development of fungal diseases. Therefore,when planting geraniums, keep the distance between the plantsabout 25 cm and keep the soil pH at the level of 6-7. It is worth placing expanded clay at the bottom of the pot, which will serve as drainage. This will make it easier to get rid of excess water andprevent geranium roots from rottingWhere possible, place geranium pots under a roof before the onset of downpours and storms. Plants should not be exposed to high temperature, as it leads to leaf burns.Proper fertilization is also important.Particularly over-fertilization with nitrogen promotes the development of fungal diseases. That is why it is worth using a special fertilizer for geraniums or flowering plants, with a reduced dose of nitrogen, and rich in phosphorus and potassium - compounds that support abundant flowering.
We should also remember that ivy-leaved pelargonium has thin shoots that are easily damaged. And pathogens can easily penetrate into broken shoots. Therefore, it is better to plant ivy-leaved geraniums only in places sheltered from the winds.
Following these rules will helpavoid geranium disease, which can cause the geranium leaves to turn yellow and dry .
Fungal diseases of pelargonium
One of the most common diseases of geraniumsis gray mold. It occurs when the humidity of both the air and the substrate is too high. Frequent sprinkling and abundant watering is an ideal environment fordevelopment of this geranium disease .
Gray mold manifests itself inbrowning leaves, watery spots and a powdery gray coating. The spots appear from the edge of the leaf and narrow towards the center of the leaf blade. The pathogen spreads rapidly to other plants through spores.
Geranium leaf affected by gray mold
Toprevent the occurrence of gray mold on geraniums , the first thing you need to do is to provide the plant with the right growing conditions. After noticing the symptoms of the disease, remove the infected parts of the plant and then spray it with the natural preparation Biosept Active.
Thepelargonium fusariosismanifests itself in a similar way. The disease begins at the base of the shoot. Leaves turn yellow and water-soaked spots appear. As time goes on, the plant becomes stunted and wilt. Fungicides that fight this disease are: Topsin M 500 SC and Dithane NeoTec 75 WG.
Equally often,geraniums attack powdery mildew and downy mildewUntreated mildew symptoms lead to complete plant degradation. These diseases are favored by high temperature and air humidity. That is why they most often appear in summer, with heavy rainfall.
Powdery mildew of pelargoniummanifests itself with a white coating on the leaves both on the upper and lower leaf, which turns brown with time.The recommended preparations for combating powdery mildew on geraniums are Fungimat AL Spray (ready-to-use preparation in a package with a sprayer) and Fungimat Concentrate (concentrate for preparing a solution for spraying).
Downy mildew of pelargoniumappears only on the underside of the leaves, as a white coating. Preparations recommended for the control of downy mildew are: Miedzan 50WP, Dithane NeoTec 75WG.
A disease that is fairly easy to recognize isgeranium rustIt is characterized by yellow, circular patches on the leaves. Often brown rust spores are visible within the stains. The leaves turn brown and fall off. The disease is favored by high humidity and too dense plantings. Remove the infected parts of the plant. The fungicides recommended for spraying are: Amistar 250 SC, Domark 100EC.
Sometimes black circular spots with a red border can be observed on the leaves and stems of geraniums. This is a symptom ofgeranium leaf spot . Over time, the plant withers and withers. For protection, the following preparations are recommended: Miedzan 50WP and Topsin M 500SC.
Decay of the base of the geranium shoot
The fungal disease that manifests itself when the geranium is pouredis rot of the stem base. The fungus lives in the substrate. It attacks the lower part of the shoot. As a result of this disease, the stem and leaves become watery and turn brown. When we notice the first symptoms, it is worth using Magnicur Energy 840 SL.
Bacterial diseases of pelargonium
The bacterial blight of geraniumsis very difficult to combat. It manifests itself on young seedlings as brown or black necroses at the base, which extend to the entire plant. On leaves of old specimens, the disease appears asbrown spots with a light borderThe plant dies very quickly. The most effective method of fighting bacterial geranium blight is to get rid of diseased plants and disinfect the substrate or its complete replacement.After acquiring new plants, preventive spraying with Biosept Active is recommended.
Pelargonium viral diseases
Another disease of pelargonium isPelargonium yellow spot virusSmall yellow star-like spots appear on the leaves, leading to necrosis. Leaves fray, this symptom is often confused with an attack by a pest. Additionally, geranium flowers lose their natural appearance.and become deformed. Similarly,pelargonium mottled virusandpelargonium mottle virus . Such viruses are transmitted with the ground and during plant reproduction. To get rid of the disease, we remove the diseased specimens along with the infected substrate.
Martyna Cieślińska
