You are happy that you can finally enjoy fresh, home-grown zucchini. Then you go out into the garden and notice that your normally green and bright zucchini leaves are losing their shine and white spots are appearing all over the leaves. Unfortunately, your zucchini has probably just fallen victim to mildew. Here's how to identify, treat and prevent powdery mildew on zucchini.
Zucchini Diseases: What is Powdery Mildew?
Powdery mildew is caused by various fungal spores that reach plants through the air and by spraying from the ground when it rains. The fungus alone is not harmful, but once it gets on your plants, it germinates and begins sucking nutrients from the surface of the plant leaves. In the final stage of mildew infection, the zucchini leaves turn yellow and crispy, causing them to shrivel and die.
Powdery mildew (see pictures) is one of the most common plant diseases, and because its appearance is so clear, it is relatively easy to recognize. This plant disease makes the leaves look like they have been dusted with talc. They are white to gray and the disease tends to occur in summer. Most of the white dust is made up of spores, which are easily spread by the wind to other nearby leaves.
Powdery mildew likes low light and temperatures of 20°C - 30°C with high humidity (over 95%). However, when the temperature rises above 32°C, some of the spores die. More about downy mildewfind out here.
Zucchini leaves turn white: prevention and control
What helps against mildew on zucchini?
A simple way to control powdery mildew is to keep the foliage of plants as dry as possible. This means that you alwaysWater from the base of the plant, instead of spraying the garden wildly with a hose.
Air circulation is particularly important
Good air circulation is also important, so you should design the space appropriately for your plants in the garden. Every plant needs enough space to grow and if you give it some space, the stems and leaves will dry faster after a rainstorm. Also make sure your plants receive plenty of sunlight.
Adequate spacing also prevents the mildew from spreading to a neighboring plant.
Cut off infected leaves with white spots
Cut off leaves that show early signs of infection as quickly as possible. Throw them in the trash and don't leave them in the compost heap. Remove and destroy all infected plants at the end of the growing season to get rid of as many spores as possible.
At the beginning of the season, cut half of the leaves from each plant to reduce the humidity around the plant and reduce the chance of infection.
Fertilize zucchini properly
Do not apply nitrogen fertilizer in the middle of the growing season. This triggers a new growth spurt, which increases susceptibility to this disease.
Home remedies for powdery mildew on zucchini – buttermilk spray
The use of a diluted milk solution in organic gardening has long been known and is used to treat a variety of plant problems. Why do milk and buttermilk work in treating fungal diseases of plants? The exact reason is not known. There are different opinions about how much you should dilute milk solutions. There is significantly less information about the correct ratio for diluting buttermilk.
The most effective dilution that has been tried is using 1 part buttermilk to 3 parts water. Simply add 60ml buttermilk and 180ml water to a spray bottle and shake the solution well. Spray the top and bottom of all zucchini leaves every 2-3 days until the mildew disappears.
Fight mildew naturally with baking soda
Another common remedy for mildew is baking powder. Add 1 teaspoon to 1 liter of water and spray the plant thoroughly.
Neem oil as a natural remedy for mildew on zucchini
Neem oil is also a common, organic treatment forFungal diseases of plants. Neem oil, obtained from the seeds and fruits of the tropical neem tree, is often used as a pesticide. It is best used preventatively before mildew becomes too severe. Be careful when using neem-based products as they are mildly toxic to fish and other aquatic life. Do not spray when bees are active.
Zucchini leaves have white spots - treat with vinegar
It's a prettysimple means: You need 1 liter of water and 1/2 tablespoon of vinegar. Fill a spray bottle with the water and vinegar solution and leave it in your garden so it is always ready to do its job. Mist the top and bottom of the leaves once a week. The reason for this spray's effectiveness is pretty simple. Mildew cannot grow in moist environments and the vinegar changes the pH of the water and the spores it encounters, which the mold also hates.
