Milk Spray Recipe For Powdery Mildew (Natural Fungicide for Plants)

Milk spray for powdery mildew is a natural garden fungicide. And if you have ever experienced powdery mildew in your vegetable garden, you’ll know that this fungal disease can cause havoc to your garden harvest. So if you’re looking to garden organically and need a solution to deal with powdery mildew than you’ve come to the right place. Try this DIY Milk Spray recipe to rid your garden of powdery mildew.

Bottle of Milk used for natural fungicide spray to control powdery mildew

One of the most common fungal diseases found in the home vegetable garden is powdery mildew. Food producing plants that are especially susceptible to powdery mildew include squash/zucchini, cucumber, pumpkin, beans and tomato plants.

This milk spray for powdery mildew is a safe solution in the garden and can be used for the life of the plant. It is worth noting that fungicide is most successful as a preventative measure. So if you see powdery mildew, take action to control it before the little problem becomes a bigger problem.

A spray bottle for making DIY milk spray

Milk Spray Recipe


1 part milk (organic if gardening organically) to 9-10 parts water.


Mix the milk and water together in a spray bottle. I use this glass spray bottle here but you can also use a plastic spray bottle or whatever you already have.

Spray the milk solution wherever you can see powdery mildew on the affected plant every 7 days.

Spray the plants during sunlight hours, preferably in the morning. Sunlight is likely to be a contributing factor to the effectiveness of this spray (more on why below).

This milk spray can be used as a preventative measure against powdery mildew. Spray plants at a frequency of every 7-14 days.

Why Does Milk Spray Work On Fungal Disease?

It’s not 100% clear why milk works against fungal disease. However, it is believed the protein in milk, along with sunlight, works as an antiseptic to fight the powdery mildew.

Because of this, it’s best to spray plants with the milk solution in sunlight.

Evidence to support the effectiveness of milk as a natural fungicide can be found in studies by Matthew J. DeBacco for the University of Connecticut. DeBacco’s research shows milk to be comparable, if not better, in some cases, than using chemical fungicides in controlling powdering mildew.

“Both organic and conventional growers could benefit from using milk in place of the fungicides typically sprayed to control powdery mildew.” – Matthew J. DeBacco

Identifying Fungal Disease – Powdery Mildew

Powdery Mildew on a tomato stem - DIY Milk Spray Natural Fungicide
Powdery Mildew on a tomato stem

As well as taking up residence in the vegetable garden, powdery mildew can be found throughout the backyard garden. Powdery mildew does not discriminate and can also be found on ornamental trees, shrubs and flowers.

Identifying powdery mildew is quite easy when you know what to look for. The fungus looks like white or gray spots (powdery), found on the plant’s leaves, stems, flowers and fruit. Powdery mildew can start as just a few dots on the plant but can quickly spread.

If fungal disease occurs early in the growing season, crops may be reduced. Although it is rare powdery mildew will actually kill a plant, it can affect the health and production of the plant.

Fungal disease can naturally occur towards the end of a plants life as part of the natural breakdown of the plant. At this point, it may be worth replacing the plant. If there’s still time in the growing season, a new, healthy plant can give you a further harvest of your favorite fruit or vegetable.

What Causes Powdery Mildew?

Powdery mildew favors soil with low moisture and humidity around the plant.

The disease can overwinter in buds of plants and other garden debris. So when the weather warms up and the conditions are right, powdery mildew can grow and spread.

The fungal spores of powdery mildew travel by wind, water and bugs, such as aphids.

Control and Prevent Powdery Mildew

To best prevent powdery mildew in your garden, give plants good airflow with plenty of growing room.

Water plants at ground level to help keep leaves dry and soil moist.

Position plants so they have adequate sunlight. Food-producing plants love at least 6 hours of sunlight a day.

Consider removing affected leaves. Especially leaves showing signs of dying off, including turning yellow, brown or curling.

As a preventative measure, use the milk spray after heavy rain. Humidity encourages powdery mildew.

Invite garden-friendly, beneficial bugs to your garden. Ladybirds love feeding off powdery mildew and will help control the problem in your garden.

Ladybird in the garden to help prevent powdery mildew
Encourage good bugs in the garden – Ladybird.


Pest and disease are a natural occurrence in the edible home garden. However, by identifying problems early and taking action with natural methods, such as this DIY milk spray, your vegetable garden will thrive. And by using natural gardening methods, you will have the healthiest, pesticide-free, garden harvest to enjoy. So why not give this milk spray a try in your food garden?

Recommended Products:

Reusable Glass Spray Bottle – plastic or glass bottles can be used to make up the Milk Spray to use on powdery mildew. I really like this option to help reduce plastic.

Plastic Spray Bottle – As above, either plastic or glass spray bottles can be used.

Related reading:

Natural Remedies To Remove Stink Bugs From Citrus Trees

Best Organic Mulch for the Garden and Natural Mulch Ideas

Natural and Organic Vegetable Garden Weed Control Methods

Uncovering the Truth: Are Coffee Grounds Good for Plants?

DIY Milk Spray

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