Baking Soda in the Garden

If you’ve been following my blog for any period of time, you’ll know I’ve been fighting battles with Septoria Leaf Spot and powdery mildew in my garden due to all the rain we’ve had this year. I’m constantly on the lookout for new and improved ways to control problems organically, and I have found another household substance that can be used in the garden – baking soda. While researching its use for fungus and mildew, I learned there are several ways to use baking soda in the garden.


As an anti-fungal, this baking soda solution is best used as a preventative, though you can use it after a plant is infected. Water your garden well a couple days prior to application, and do not apply in full sun. Mix together:

  • 1 gallon water
  • 1 tablespoon baking soda
  • 1/2 teaspoon castille soap
  • 1 tablespoon horticultural oil

Apply especially during times of humid or wet weather, and be sure to get lower leaves of plants. If your plants are infected, remove affected leaves before applying. Reapply every 7 days.

NOTE: Do not store this solution. Also, while spraying, agitate your sprayer so that the solution stays mixed together.

I’m going to try this on my tomatoes and see if it helps against the Septoria Leaf Spot. That way, I don’t have to use the copper fungicide every week.


The above recipe can also be used against downy mildew and powdery mildew.

For downy mildew, remove affected leaves and spray solution weekly.

For powdery mildew, the spray will not eradicate the disease; but it will help it not to spread. Hose down the affected plant to dislodge the spores. After the leaves dry, spray the plant generously with baking soda solution.

I’ll be replanting cucumbers and squash next month, and they seem to be prone to mildew. I’ll try this as a preventative treatment on them, and also as a treatment on my cantaloupe, which seems to be developing mildew.


Pour dry baking soda, full strength, into cracks in your sidewalk or patio to kill weeds and prevent their regrowth. For weeds in other areas, wet the weeds then apply about a teaspoon of baking soda directly onto the weed. Be sure you do not get baking soda on or around your good plants. You don’t want to kill them!

I have several weeds growing up through the rocks in my fire pit. Guess where I’ll be using this first?


Although using row covers to prevent moths from laying the eggs that create cabbage loopers/worms is the best preventative to having your brassicas eaten, most people don’t use row covers. If you see those pesky worms eating your cabbage, kale, or turnips, you can apply a 50/50 mix of flour and baking soda to the leaves. Use a bottle that allows you to sprinkle the mixture onto the plants and keep handy for re-applying every couple of days or after a rain. When the worms eat the leaves with the mixture on them, they will die. Be careful not to sprinkle too much onto the leaves, getting it on the ground. Baking soda WILL affect the pH of your soil, making it more alkaline.

If I see any of those nasty critters on my fall crops this year, I’ll be armed and dangerous.


Every gardener knows what it’s like to try to clean our hands and nails after a good session in the dirt. Well, I’ve read that using a little baking soda while washing your hands will help get the dirt off. I’m going to try that next time I have more dirt on my hands than what I left in the garden.


Have you used baking soda in your garden? How did it work for you?


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