There are many things that could threaten the health of your beautiful hydrangeas. Powdery mildew on hydrangeas is one of the most common diseases that affect the plants. Fortunately, there are some methods and home remedies that you can use to easily prevent and combat the fungal disease.
Hydrangeas are very popular with gardeners in summer because of their large, colorful flowers. The magnificent plants are real eye-catchers in the garden, unless they are not affected by mildew. Although they typically grow healthy and vigorous, they are susceptible to the fungal disease that forms a powder-like substance on the plant's leaves. However, there are measures you can take to ensure that your beautiful shrubs do not fall victim to this disease.
Powdery mildew on hydrangeas: How to prevent and combat the fungal disease
Powdery mildew is one of the common plant problems in hydrangeas. Unfortunately, the conditions that favor the flowering shrub also favor the pathogens spread by air currents and direct contact with other plants. Powdery mildew does not usually kill plants, but it makes them look unsightly and can weaken them and cause poor growth. Read on to learn what causes powdery mildew on hydrangeas and how to control it.
How do you recognize powdery mildew on hydrangeas?
Powdery mildew is a fungal disease that affects the leaves, young shoots and flowers of hydrangeas. This makes a distinction between two types of the disease, powdery mildew and downy mildew. The main difference is that powdery mildew leaves a white to grayish, powdery coating on both sides of the leaves, stems and flowers, while downy mildewleaves the leaves hangingand causing yellow and brown spots on the underside.
The severely affected leaves often fall off the plant and the young shoots can die.
Powdery mildew does not require moist leaf surfaces to develop and typically occurs in dry weather with warm days and cool nights common in spring and fall.
It most commonly affects plants in heavily shaded areas and although all hydrangea species are susceptible, the large-leaved hydrangea (Hydrangea macrophylla) is most affected.
If left untreated, the disease can infect the newly emerging buds and stunt their growth.
Treat mildew on hydrangeas with dish soap and baking soda
Once mildew has developed, treatment should be carried out as quickly as possible. First, remove all affected leaves and parts of the plant unless the problem is so severe that the entire plant is affected.
Mix two to three drops of dishwashing liquid with 1/2 tablespoon of baking soda and 2 liters of water and spray the hydrangea leaves with the solution weekly until the disease disappears. Cover the affected plant evenly, paying particular attention to the underside of the leaves and stems. Also treat any nearby susceptible plants. This changes the pH and prevents the mildew from forming or spreading.
Other home remedies to combat mildew
- Milch:Mix 1 part milk with 2 to 3 parts water in a spray bottle and spray the hydrangeas generously as soon as the first signs of mildew appear. It is best to use whole or raw milk for the best results. Treat plants in sunlight as it is thought that milk's antifungal properties are enhanced by sunlight. The naturally occurring compounds in milk not only fight disease, but they also strengthen the plant's immune system. Repeat the treatment every 10 to 14 days until the plant recovers or until weather conditions are no longer warm and humid.
- Neem oilis an effective remedy when used at the first symptoms, such as small white spots on the leaves. It kills the mildew spores. Do not use neem oil in the middle of the day as direct sunlight can burn the leaves. Mix 2 tablespoons of dish soap with 4 liters of water and then add 4 teaspoons of neem oil. Test the foliar spray on a small portion of the affected plant to ensure no adverse reactions occur. Then mist the entire hydrangea and repeat the process every other day for the next 14 days.
Prevent powdery mildew on hydrangeas
While there are many treatment options, you should primarily focus on preventing this fungal disease.
To reduce the risk of infection, be sure to leave plenty of space between hydrangeas to ensure good air circulation and that you place them in a slightly sunny locationPlant location.
Choose resistant species that are less susceptible to powdery mildew.
It is best to water the hydrangeas at the base and avoid watering from above to prevent the spread of spores from leaf to leaf.
Also interesting:Fight mildew with home remedies: What you can do against powdery mildew and downy mildew!
