Controlling The Fungus Among Us
If you’re growing any gourds this year, this easy homemade fungicide recipe might just come in handy for you. Curcurbits like cucumbers, squash, pumpkins, and watermelon are notoriously prone to a fungal disease that’s known as powdery mildew.
And as you’ll see below, this simple recipe can also be used to treat other fungus issues around the garden. It is also widely used by rose aficionados to help control the black spot fungus that is a common problem for rose bushes.
Is Powdery Mildew Consuming Your Cucumbers?
Powdery mildew is easily recognizable in an otherwise healthy garden. When this fungus goes unchecked, it often looks like someone has used a flour sifter to apply a thin coat of flour across the leaves of affected plants.
Powdery mildew can pop up on other garden plants, too. Some other plants that are especially prone to this fungal issue include phlox, bee balm, roses, apples, and grapes.
Make Your Own Homemade Garden Fungicide
The basic recipe I have had success with comes from The Natural Gardener in Austin. The recipe they recommend is as follows (link to original recipe here):
4 Level teaspoons or 1 1/3 tablespoons of Baking Soda
1 teaspoon of Mild Soap (Dawn, Ivory, should be biodegradable with no phosphates)
1 gallon of Water
Mix all ingredients thoroughly and keep agitated. Then spray plants.
Spray all leaves thoroughly, until the solution begins to run off. Spray the top and bottom of affected leaves, and spray all of the small new leaves, even if they don’t appear to have the fungus yet.
Read More: Colloidal Silver as a Fungicide
Peer Reviewed and Scientist Approved
Gardeners might be infamous for passing along myths and legends, but this simple fungicide has some pretty good academic credentials. Dr. R. Kenneth Horst from Cornell University led a series of studies to document the effectiveness of baking soda as a fungicide.
His studies found that a 0.5% solution of baking soda is best to control powdery mildew in curcurbits, and he found that using a surfactant (like soap or horticultural oil) is necessary to make the solution effective. You can find lots of information about Dr. Horst’s work, and other relevant research, in this document from the National Center for Appropriate Technology:
View or Download the Original File Here: Use of Baking Soda as a Fungicide
Natural Alternatives for Controlling Fungal Issues
Before you start breaking out the fungicides, consider whether or not you might be able to control the issue just by adjusting your watering schedule. Powdery mildew can spring up during exceptionally dry conditions, especially when you have hot, dry days and cool nights. If you are growing plants that are susceptible to drought stress, make sure that they are getting regular water during summer hot streaks.
Air circulation is one of the biggest factors in many fungal infections, and you might be able to control powdery mildew and other fungal issues by spacing plants further apart and pruning selectively to increase air flow through the affected area.
And if you’ve had problems with powdery mildew in the past, one of the best things you can do is be sure to select plants that are resistant to powdery mildew in the future. Some varieties are less susceptible to the fungus, and they are advertised as being resistant in seed catalogs and garden centers.
1: Baking Soda Fungicide, The Natural Gardener. https://www.naturalgardeneraustin.com/baking-soda-fungicide.html
2: The Organic Gardener’s Handbook of Natural Pest and Disease Control. Ellis, Barbara W. and Martin, Deborah L. 2009. Rodale.
3: Use of Baking Soda as a Fungicide. Appropriate Technology Transfer for Rural Areas, National Center for Appropriate Technology, USDA. http://www.attra.org/attra-pub/bakingsoda.html
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