Fight powdery mildew on roses

There are a variety of measures that can help remove the white coating on the rose petals again. But it is also helpful to make sure in advance that this plant disease does not break out in the first place.

Different types of powdery mildew

If you notice powdery mildew on your roses, you should definitely look carefully. Because there are two different types of this fungus infestation, which is also called fair-weather fungus. Both variants, however, have the same spreading via spores, which form a dense network of very fine fibers on the plant. Experts also call this mycelium.
Both the so-called "powdery mildew" and the "Downy mildew"A white to gray fur forms on the roses, which is mainly visible on the upper side of the leaves. This can simply be wiped off with a damp cloth. If the infestation is more pronounced, however, the buds and the shoot tips are usually also affected and crippled. The leaves of infested rose plants appear bulging and brown at the tips. This brings the growth of the roses to a standstill.

Rapid distribution under special climatic conditions

Real powdery mildew on roses is particularly evident in phases with nice, dry weather, which is, however, accompanied by night dew. It is therefore clear that especially sunny days in spring and autumn create the ideal living conditions for this fungal attack. If nothing has been done to combat this pest until late autumn, dark winter fruiting bodies will form, which can overwinter in leaves and plant remains on the ground.

Downy mildew is not always clearly recognizable

In contrast to the whitish coating in powdery mildew, downy powdery mildew mainly forms reddish-purple spots on the upper side of the leaves of the roses. There may be yellow and brown spots on the leaves, which are limited by leaf veins. On the other hand, a gray fungus coating forms on the underside of the leaves, which is soft to the touch. The downy mildew infestation can go so far that the buds and shoots of the roses are also attacked.
In contrast to the warm and dry conditions that right powdery mildew needs to grow, downy mildew mainly spreads in damp and only moderately warm climates. Excessive nitrogen content in the soil of the plant also contributes to infestation with this pest. If you want to protect yourself against powdery mildew when buying your rose plants, you should pay attention to a declaration of the plant with the wording "against race 1 - 26". This means that the roses are immune to certain subspecies of the fungus, which repeatedly develop new resistances.

Fight powdery mildew with simple home remedies

For many garden owners and plant lovers, it is important to spare their garden from chemical clubs in pesticides. If you are worried because your roses are infected with powdery mildew, you can also use simple home remedies:

• Milk in particular has proven its worth here, with fresh milk in particular being used.
• You simply mix one part milk with nine parts water and spray this mixture on the infested plants at close range.
• The microorganisms contained in the milk usually fight the fungal attack very successfully, which also makes it clear why it has to be fresh milk and why long-life milk is not suitable for use.
• The lecithin contained in the milk works against powdery mildew and the sodium phosphate strengthens the immune system of the rose plant.
• This achieves two important results with one relatively simple measure, which should be carried out about two to three times a week if necessary.

Further precautions are recommended

In general, the natural resistance of the rose plant offers the best protection against fungal attack. Especially with bed and shrub roses, but also with ground-covering varieties, there are already many varieties that are less susceptible to pests such as powdery mildew. Those who prefer hybrid tea and hybrid tea should know that the Resistance breeding is still at the beginning and the garden owner is therefore entitled to individual measures meet are. Generally recommended:

• regular removal of plant debris
• Separation of infected parts of the plant and safe disposal
• Also meticulously clean garden tools or growth aids, preferably with an antiseptic
• Always wear gloves when treating diseased roses
• Apply chemical pesticides only directly to the diseased rose

Prevention is better than treatment

As in many other areas, the principle applies to healthy and beautiful growth of roses in the garden that prevention is more effective than the best pesticide afterwards. Even when choosing the plants, you can take precautions by carefully considering the soil and sun conditions at the planting location.
In addition to regular care and fertilization, the plants should also be pruned regularly, because this is a promotional measure for the health and growth of the plant and looks nowhere near as radical as a pruning that removes diseased or infected parts of the plant target. The rose in particular recovers from this very slowly and with great difficulty.
With individual care tips and observing the growth of roses and the development of flowers, harmful infestations such as powdery mildew can be prevented. This not only saves time and costs for control, but also enables the rose to have a long, healthy lifespan, which rewards it with wonderful flowers in all their splendid colors.

Worth knowing about rose powdery mildew in brief

• Powdery mildew is a collective name for various plant diseases caused by fungi.
• It usually occurs through a white coating, the so-called. Mushroom lawn, on the leaf surfaces.

A distinction is made between the real and the false mildew: The pathogens of powdery mildew belong to the hose fungus and mainly attack leaves. First the leaves are covered with a flour-like coating and later turn brown until they dry up and fall off. Downy mildew is one of the fungi and penetrates the plant. It shows itself by a white coating on the underside of the leaves.

• In agriculture and horticulture, fungicides with a chemical structure are used against the various types of mildew.
• The powdery mildew fungus usually comes with a Pesticides based on sulfur used.

For example, while powdery mildew is harmful to plants, an intact ecosystem needs powdery mildew for some Ladybug species. The sixteen-spotted, twenty-two-spotted and sixteen-spotted ladybirds feed exclusively on powdery mildew, so this plant disease is vital for these species.

In the German gardens, roses in particular are affected by powdery mildew. Very sensitive Rose varieties can be severely weakened by this disease. The fungal spores spread through the wind and require moist leaves to germinate. For this purpose, the formation of dew at night is usually sufficient.

• To prevent powdery mildew, you should Roses plant only in moist and nutrient-rich soil in a sunny location.
• The soil should be particularly rich in potassium, because this strengthens the immune system Roses.
• Furthermore, susceptible roses should be as bright as possible and not watered much.
• The Plants with fertilizer starch and repot in a fresh container.
• The leaves should be kept dry and thus protected from rain.

An old home remedy for powdery mildew is baking soda and oil mixed together and dusted on the plant. Mix three packets of baking powder with 50 ml of cooking oil and add a few splashes of washing-up liquid as an emulsifier and spray endangered plants with it every ten to 14 days in the evening. The floury topping disappears quickly and what looks damaged after a few days can simply be cut out.
Basically, you need a lot of patience to fight powdery mildew, although you shouldn't wait too long if you get an infestation, because the rose is quickly weakened and wilted.