Powdery Mildew of on a rosebud

Powdery Mildew: Organic Controls

Organic GreenCure for Powdery Mildew

Chemical controls for powdery mildew range from harmless substances, such as milk and whey, to hardcore synthetic fungicides. It is important to start with your organic options first, let’s take a look at one of our favorite antifungal organic options for powdery mildew, GreenCure.

What Am I Putting on My Plants?

When it comes to fungicides (organic or not), GreenCure is a product that deserves serious consideration. It consists primarily of potassium bicarbonate (which is used in human food), dietary supplements, and antacids.  This active ingredient is similar to baking soda (sodium bicarbonate). While both bicarbonates can be used as a fungicide, studies show that the potassium version is 25-35 times more effective. Not only is it safe for you, it’s also safe for our environment. The USDA, FDA, and EPA all recognize its safety. GreenCure is one of the few fungicides registered for indoor use by the EPA.

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Powdery Mildew: Biological Controls

Biological controls are living organisms used to prevent and treat pests in your garden. One great benefit of utilizing biological controls is that it allows you to be approved for certified organic gardening due to the absence of chemicals.

Why Should I Use Biological Controls?

Compost teas and products like Photosynthesis Plus, Actinovate, & Serenade contain numerous microorganisms (microbes). When you spray them onto your plants, these beneficial little lifeforms fight the good fight against the pathogenic ones. In addition to killing fungi, like powdery mildew, they can also prevent them in the following ways: increased overall plant health, improved disease resistance and by establishing beneficial microbial colonies which occupy space and consume plant byproducts that could otherwise end up supporting disease. In other words, you use these little buggers to create a militia of good guys that kick out the rowdy ones that would otherwise be hanging around and eating your goods.

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Powdery Mildew Prevention II: Gardening Techniques

Ignorance is NOT Bliss

Powdery Mildew is a powerful force that is worthy of your time and prevention efforts. It is undeniable that there are lots of spores in our environment but there are also a lot of ways to deny them. There is no use in claiming ignorance.  Spores present a real garden threat and they won’t be disappearing from the planet unless we do (and they might still be around after that). We’re talking about keeping them out of our garden and stopping them from breeding if they do find their way in.

The Power of Denial

Although you may be looking at how to prevent powdery mildew from affecting your indoor garden you have to work from the outside in. In order to keep spores outdoors, take steps to ensure that you and your friends are not going from another garden (especially an outdoor garden) directly into another garden without showering and changing clothes. It may seem melodramatic but remember, we’re dealing with a phantom menace. A Way to Grow gardener shared, that after unsuccessfully fighting PM for some time, he finally came to realize that he was bringing in spores from some infected rose bushes he continually walked past when entering his house.

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Powdery mildew on cucurbit leaves

Powdery Mildew Prevention I: Garden Design & Climate Control

How Garden Design & Climate Control Can Help Prevent Powdery Mildew

So the background check into powdery mildew spores confirms that they can be a habitual offender, a persistent pain in the ass. If your plants have ever been afflicted, then you know PM is a menace. What makes PM a phantom menace? Standard definitions of ‘phantom’ suggest something unreal, like a ghost. That obviously doesn’t apply here. Ask any gardener who has dealt with PM: it’s all too real. Ask that same person how they feel about PM and they may well touch on other definitions of phantom: something hated, feared, or deceptive.

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Petri dish with spores growing

Powdery Mildew Spores

Powdery mildew Spores are Already in Your Garden

While this may sound alarmist, it’s not an unrealistic or paranoid exaggeration.

The Power of Spores

Consider the nature of spores; they exist to reproduce. Not to mention, they are invincible. They can survive in all weather extremes for long periods of time, travel great distances, and there are lots of them in our environment. Studies look at how far above and below us they exist in order to help define the limits of our biosphere.

Spores are pretty powerful stuff. The theory of panspermia suggests that spores may have brought life to our planet. Did you know that spores can survive space travel, radical ethnobotanist and native Coloradoan Terence Mckenna even proposes that connections exist between spores, earthlings, and aliens? Isn’t wild that spores not only create life but are also intelligent and able to communicate? Really?! How do gardeners stand a chance?

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Powdery Mildew Pinnate Leaves

Hello, My Name is Powdery Mildew

Powdery Mildew May Be Your Arch-Nemesis! 

Powdery mildew is a major challenge for both global food producers and small scale gardeners. There are a number of ways to reduce your risk of becoming a victim of this pesky mildew.

Prevention is Your Bestie

First and foremost, prevention is key. As the saying goes, “an ounce of prevention is worth a pound of cure”. Once it is in your environment, it is very difficult to eradicate. Taking preventative measures will help to mitigate risk and potentially save your garden from infestation.  

Weather Resistant

Powdery mildew spores are very hardy and weather resistant. They can even survive throughout the winter. Carefully screen any plants before bringing outdoor plants indoors for the colder season or when integrating new plants into your grow. Examine both sides of the leaves, fruits, and stems. If you have space, consider creating a ‘quarantine’ area where you can put new plants for the first few weeks. This may seem like a drastic step but consider that eradicating powdery mildew can be a significant amount of work.

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