What are fungal diseases

Fungal diseases

General

Fungal diseases in garden plants are a common evil. Often you can prevent the worst by just taking precautions. The right choice of location is one of the most important requirements for healthy garden plants. Healthy seeds and plants prevent the introduction of pathogens. Loosening the soil to improve the growth conditions and improving the soil with sand, bentonite or compost can increase fertility and promote soil life. Sowing or planting garden plants at the right time, optimal nutrition with organic slow-release fertilizers, preventive treatments with plant strengtheners, as well as crop rotation and mixed cultures also promote the natural defense mechanisms. When watering the plants, it is important not to wet the leaves so that fungal spores cannot germinate so easily. Regularly thinned fruit trees and vegetable and perennial species planted at a sufficient distance dry quickly after rainfall.

Wrong mildew

Downy mildew affects ornamental plants, cucumbers, radishes, radishes, lettuce, peas, lettuce, cabbage, spinach, onions and grapevines. If anything, the fungal coating occurs on the underside of the leaf. On the other hand, the yellow, later brown spots on the upper side, which are usually bordered by the leaf veins, are more noticeable. Ask in stores about resistant varieties and treat susceptible plants preventively with biological preparations based on sulfur or copper.

Rust fungi

Rust fungi cause very noticeable symptoms. They grow in the leaves; yellowish to red-brown rust pustules with spores are usually formed on the underside of the leaves to spread. Rust fungi can change host like the pear grate, the main host of which is the Sad tree (Juniperus sabina). It also infects the Chinese juniper (Juniperus chinensis) and the Virginian juniper (Juniperus virginiana). They can only be combated with fungicides or by removing intermediate or main hosts in the area. By the way: Because the grain rust caused great damage in agriculture in the past, the culture of the intermediate host - the local barberry (Berberis vulgaris) - was even banned for a long time.

Apple scab

You can recognize apple scab after flowering by green-black, later brown-black spots on the upper side of the leaves. The leaves fall early, and the peel of infected fruits cracks. Varieties such as ’Prima’, ’Florina’ and ’Sir Prize’ are relatively resistant. As a preventive measure, you should mulch tree grates with compost, water the trees well, thin them out regularly and remove the fallen leaves. After flowering, preventive sharpening with network sulfur makes sense in damp weather.

Leaf spot pathogen

Leaf spot pathogens cause all kinds of spots. These are red or white, for example in the case of red or white spot disease on strawberries, black (tar spot disease on maples), yellow, brown or gray (Septoria leaf spots on tomatoes), large and star-shaped or tiny and plump. General preventive measures against fungal diseases can prevent infection. Most leaf spot diseases, however, are not severe enough to require the use of fungicides.

Powdery mildew

Powdery mildew always appears as a wipeable, white, later brownish coating on the upper side of the leaves. The leaves turn brown and dry up. It occurs particularly in roses and other ornamental plants, cucumbers, peas, zucchini, pumpkin, lamb's lettuce, apples, gooseberries and black currants. You should remove diseased leaves and shoots and, in the event of an infection in the previous year, spray the plants preventively with WG network sulfur.

Gray mold

Gray mold attacks many ornamental plants such as peonies, strawberries, grapevines, cucumbers and lettuce. Infested areas rot and are covered with a grayish lawn of mold. Gray mold mainly spreads on weakened, over-fertilized plants or when there is increased moisture. You should choose a dry, airy and light location for endangered plants and remove diseased plant parts as early as possible. Spraying with homemade plant strengtheners such as horsetail broth make endangered plants more resistant.

Wilt fungi can attack almost all garden plants. They usually penetrate through damaged roots and destroy or block the vessels, so that individual shoots are cut off from the water supply and wither. A typical damage pattern of so-called Verticillium wilt in woody plants is that often not the entire plant wilts, but initially only individual branches. Most plants such as the Japanese maple (Acer palmatum) are particularly susceptible to the fungal disease on unsuitable, very loamy and air-poor soils. You should avoid damaging the roots and, if necessary, loosen the soil extensively and deeply before planting. Infested trees can sometimes be saved if they are transplanted to a more favorable location in good time. Clematis hybrids that are attacked by the clematis wilt usually sprout again when they have been planted deep enough. The surface of the pot ball should be about a hand's breadth below the surface of the earth

Practice video: fighting powdery mildew

Do you have a plant in your garden that has powdery mildew? We will show you which simple home remedy you can use to get the problem under control.
Credit: MSG / Camera + Editing: Marc Wilhelm / Sound: Annika Gnädig