How To Prevent and Cure Powdery Mildew on Pumpkins (2022)

There are few things that signal fall as effectively as fresh pumpkins picked straight from the patch. But if you’re heading out to your patch and end up finding leaves coated with a white substance, then it’s time to take action.

This means your pumpkins have powdery mildew, and if you’re not careful, it can take out your entire patch and ruin all of the hard work that you’ve put into them. But there’s good news. If you have powdery mildew on pumpkins, there are a few different products that can clear it up for you in no time at all.

Not only did we highlight the five best products to get powdery mildew off pumpkins, but we also came up with a comprehensive buyer’s guide, and even answered some of the most frequently asked questions for you here.

Prevent and Cure Powdery Mildew on Pumpkin


  • Super easy to apply
  • Very affordable
  • Organic product
  • Organic product
  • Fights all kinds of diseases
  • Easy to use
  • Super easy to apply
  • Organic product
  • Very effective product

5 Best Powdery Mildew Fungicides

1. Bonide 811 Copper 4E Fungicide – Top Pick

[lasso amazon_url=”″ id=”3075″ ref=”bonide-811-copper-4e-fungicide-16oz-473ml” link_id=”2638″]

Size: 16 ounces

Style: Concentrate

Application Method: hose-end sprayer or tank sprayer

If you’re looking for the best possible powdery mildew fungicide out there, it’s hard to beat what Bonide 811 Copper 4E Fungicide offers. It’s an outstanding mix of price and performance, and it’s easy to apply to larger pumpkin patches too!

So, whether you own a large community patch or are just growing a few plants in your backyard, then Bonide 811 Copper 4E fungicide can keep powdery mildew at bay. It’s a completely organic product that’s easy to use. And while it kills and prevents powdery mildew, it also treats and prevents plenty of other fungal infections too.

However, keep in mind that you’ll need to mix this fungicide by yourself, and you’ll need either a hose-end sprayer or a tank sprayer to use it after that. This is an additional cost that you’ll need to factor in when you’re treating your pumpkins.


  • Great mix of price and performance
  • Outstanding for larger applications
  • Organic product
  • Fights all kinds of diseases
  • Easy to use


  • You need a separate sprayer
  • You need to mix it yourself

2. Garden Safe Brand Fungicide3 – Best Budget

[lasso amazon_url=”″ id=”3073″ ref=”garden-safe-brand-fungicide3-ready-to-use-24-ounce” link_id=”2639″]

Size: 24 ounces

Style: Ready to use

Application Method: Direct spray

When you’re on a tight budget but have powdery mildew starting to take over your garden, then Garden Safe Brand Fungicide3 can bail you out. It’s an extremely affordable product that’s even easier to use – and it’s super effective.

This is a ready-to-use direct spray product, which means all you need to do to eliminate the powdery mildew is point the nozzle at the leaves and spray! Even better for your garden is the fact that it’s also an insecticide and miticide, which means you won’t have to deal with those coming in and taking over your plants either!

But even though it has all these features it’s still completely organic, making it perfectly safe for children, pets, and other wildlife around your garden. However, keep in mind that while a direct spray is easy to use, it also means using a lot of product, as well as a lot of spraying for larger gardens.

Moreover, you need to reapply every two weeks to get all the preventative benefits out there. Because of that, we recommend Garden Safe Brand Fungicide3 for smaller gardens. If you’re running a larger application then this isn’t the most cost-effective option.


  • Super easy to apply
  • Very affordable
  • Organic product
  • Also works as an insecticide and miticide


  • Not the best for larger gardens
  • Needs to be reapplied every two weeks

3. Dr. Earth 8007 Ready to Use Disease Control Fungicide – Premium Choice

[lasso amazon_url=”″ id=”3077″ ref=”dr-earth-8007-ready-to-use-disease-control-fungicide-24-ounce” link_id=”2640″]

Size: 24 ounces

Style: Ready to use

Application Method: Direct spray

If you have powdery mildew and need to get it under control right away, then Dr. Earth 8007 Ready to Use Disease Control Fungicide is exactly what you need. It’s another ready-to-use direct spray product, which means it’s super user-friendly.

Now it’s only a fungicide, which means you don’t get any insecticide or miticide benefits from using it. However, considering how effective it is against fungi like powdery mildew, it’s not hard to see how it’s our premium choice.

It’s still completely organic, which is a huge deal for fruit and vegetable plants. However, it is a more expensive product for how far it goes, but it does come in a larger container. So, while it’s more expensive per ounce than our budget choice, it’s not by as much as you might think at first.


  • Super easy to apply
  • Organic product
  • Very effective product
  • Comes in a larger size


  • Not the best for larger gardens
  • Only works as a fungicide

4. Bonide Products INC 142 Sulfur Plant Fungicide – Best for Large Gardens

[lasso amazon_url=”″ id=”3200″ ref=”bonide-products-inc-142-sulfur-plant-fungicide-organically-controls-rust-leaf-spot-and-powdery-mildew-4-lbs-2″ link_id=”2641″]

Size: 8 pounds

Style: Dust/Spray

Application Method: hose-end sprayer, tank sprayer, or spreader

When you have a massive garden or pumpkin patch, the last thing you want to do is to use a direct spray bottle to treat each plant individually. That’s where Bonide Products INC 142 Sulfur Plant Fungicide comes in. It’s another organic product, making it perfectly safe to use in your garden, but it also comes with more application methods than any other option on our list.

If you have a young garden or patch then you can put the mixture into a spreader and treat your garden, but you can also mix it into a hose-end sprayer or a tank sprayer to treat your garden too. This means you’ll have to mix everything yourself, but that’s the most cost-effective way to do things.

And since Bonide Products INC 142 Sulfur Plant Fungicide gives you eight pounds of product, that means it goes far further and lasts longer than just about any other product on our list.

Just keep in mind that it only acts as a fungicide, so if you’re looking for an all-in-one product that acts as an insecticide and a miticide to treat your garden, then this might not be the best fit. But for those that simply want the best powdery mildew killer and preventer for large gardens, then this is it.


  • Comes with tons of product
  • Easy to apply over large gardens
  • Organic product
  • Multiple ways to apply
  • Works on multiple fungal diseases


  • You need a separate application tool
  • Only acts as a fungicide

5. Bonide 813 Fungicide – Easiest Application

[lasso amazon_url=”″ id=”3201″ ref=”bonide-813-fungicide-1-pt-clear” link_id=”2642″]

Size: 16 ounces

Style: Ready to use

Application Method: Garden hose attachment

If you have a larger garden or pumpkin patch and are looking for the easiest fungicide to apply over a large area, then Bonide 813 Fungicide might be exactly what you’ve been looking for. It’s a concentrate formula, but it comes in a ready-to-use bottle that has a garden hose attachment on it.

To use it all you need to do is hook up the garden hose and start spraying your garden! This attachment lets each bottle go farther, gives you more protection, and also makes it easier to apply it over large areas compared to a direct spray option.

It’s still an organic product, which means you’re not putting any harmful chemicals near your food. However, when you look at the price of each bottle, you’ll notice that you’re paying far more than if you invested in a garden hose attachment or a tank sprayer and bought the concentrate and mixed it yourself.

So, if you think you’ll need to do this more than once, or you plan on spraying year after year, then it might be a better investment to get a separate tank sprayer and mix the concentrate yourself.


  • Easy to apply to larger gardens
  • Organic product
  • Super easy to use


  • More expensive option
  • Doesn’t give precise application
  • Not the largest size

Buyer’s Guide

If you still have questions about powdery mildew on pumpkins and what product is right for you after reading the reviews, we’ve got you covered here. Just read through this comprehensive buyer’s guide, and we’ll walk you through everything you need to know to get your fungal infection under control in no time.

What Is Powdery Mildew

What Is Powdery Mildew?

Powdery mildew is an extremely common fungal infection that can infect a wide array of plants. It presents itself as a white powdery-looking substance that covers the leaves of your plants.

But while it might look like a powder you won’t be able to brush it off, and you’ll find it spreads like wildfire all throughout your garden, not just the plant it’s on. Because of this, you want to treat for powdery mildew as soon as you see it.

If you wait until it spreads then you might find that it’s on far more plants and that it takes a few extra applications to get it under control.

How Does Powdery Mildew Hurt Your Plants?

Compared to many viruses’ powdery mildew might not seem like the most detrimental virus. Powdery mildew doesn’t have any negative effects on your plants except for one very significant way.

Powdery mildew blocks leaves from completing photosynthesis, and the less energy your plant has, the less likely it is to produce viable fruit. Not only that, but since powdery mildew spreads extremely fast, it can quickly overtake the entire plant and prevent it from getting enough photosynthesis to simply survive.

To make matters worse, since it spreads via airborne particles it quickly infests every single plant in your garden. So, while those small white spots on a single pumpkin plant might not seem like much now, if you leave them alone for too long then they can quickly take over your garden and ruin the entire harvest.

Preventing Powdery Mildew

Because treating any problem can be more challenging than preventing it in the first place, it’s often best to prevent the problem from taking root in the first place. The problem is that preventing powdery mildew is one of the more challenging tasks to complete.

That’s because preventing powdery mildew has nothing to do with properly caring for your plants. Even if you do everything right, your plants can still get a powdery mildew infection. That’s because it spreads via airborne particles, so simply having your plants outside exposes them to powdery mildew.

So, if you’re trying to prevent powdery mildew from getting on your pumpkins, the best thing you can do is to apply a preventive fungicide. The good news is that any of the products on our list will work.

Just ensure that you don’t overdo it as this can be harmful to your pumpkin patch. But if you follow the application instructions on the product, you choose you can avoid powdery mildew from getting a foothold in your garden without any negative side effects.

The Importance of Organic

Any time you’re applying products to a vegetable or fruit plant, you need to be extremely careful with what you’re putting on it. One of the perks of having your own home garden is that you get to control the chemicals you’re exposing the food to.

Because while non-organic products might swear up and down that they’re safe to use around your food, when you look at the fine print, you’re only supposed to eat the fruit a few days after applying the fungicide, which can also have negative impacts to the surrounding environment.

Since organic products do a phenomenal job at eliminating and preventing powdery mildew, we can’t find a reason to go with a non-organic product – even if it is a little bit cheaper and lasts a bit longer.

Applying Your Fungicide

While we’d love to tell you exactly how to apply the fungicide you choose, the truth is that it differs a bit depending on the product you choose. Because of this, the best we can do is recommend that you follow the exact instructions on the product you choose.

Still, we’ll break down the three most common application methods below.

Direct Spray

Direct spray products are the easiest to use, but if you’re trying to apply them to larger gardens, then it can be a bit more work. They come in a Windex-style spray bottle, and all you need to do to use them is point them at the infected plant and pull the trigger.

Garden Hose Attachment

Just because it’s not a direct spray bottle doesn’t mean it can’t come in ready-to-use packaging. Another option is those that come with a garden hose attachment application method. All you need to do is hook up a garden hose to the spray bottle and water your garden.

This makes it easier to cover larger areas, but you still get the convenience of a ready-to-use spray, it’s a win-win.


The final option you have to choose from when you’re picking a fungicide are concentrates. Concentrates give you the best value, but you have to mix everything up yourself. Not only that, but you need to have a garden hose attachment or a tank sprayer to finish the job.

So, while you get the best possible price by choosing a concentrate, if you don’t have the extra equipment, you’re going to spend more the first time you get everything you need.

Final Thoughts

When you’re dealing with powdery mildew on pumpkins, you don’t want to mess around with products that don’t really work. The longer you wait the more the infection will spread, and the more it will damage your final yield.

So, what are you waiting for? Get the perfect fungicide to get that powdery mildew infestation off your pumpkins as soon as you can!


If you still have questions after reading through our guide on powdery mildew on pumpkins, you’re not alone. That’s why we decided to answer some of the most frequently asked questions right here.

How Do I Get Rid of Powdery Mildew?

Because of its invasive nature and the fact that it spreads via air spores, the only way to effectively eliminate powdery mildew on your pumpkins is with a fungicide. Commercial fungicides work best since they are specifically tailored to tackle fungal infections like powdery mildew.

What Is a Natural Remedy for Powdery Mildew?

While we prefer commercial fungicides, there is a natural remedy you can try. Simply mix one tablespoon of baking soda with a tablespoon of vegetable oil, one teaspoon of dish soap, and a gallon of water.

You’ll still need a spray bottle, but an empty Windex-style spray bottle should do the trick.

How Do You Treat Downy Mildew on Pumpkin Plants?

We recommend treating downy mildew on pumpkin plants with Bonide 811 Copper 4E Fungicide. It’s an extremely effective fungicide, and it can take out and prevent downy mildew with ease!

What Is Powdery Mildew Caused By?

Powdery mildew is a fungal infection that spreads via air spores. It blows through the air, and when it lands on an untreated leaf, it can take root and start a new colony. Because of this, there is almost no way to prevent powdery mildew without treating your plants properly.

Leave a Comment