Monterey Bi-Carb Old Fashioned Fungicide

Monterey Bi-Carb Old Fashioned Fungicide

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Product Overview

Monterey Bi-Carb Old Fashioned Fungicide is a potassium bicarbonate powder that effectively controls and eradicates powdery mildew on contact on ornamentals, fruit trees, grapes, vegetables and roses. For best results, apply at the first sign of powdery mildew. It is best to apply early before the mildew has become well established. Application can be repeated every 7 to 10 days as necessary. Monterey Bi-Carb Old Fashioned Fungicide can be applied on fruits and vegetables within one day of harvest.

Features and Specs

Active Ingredient: Potassium bicarbonate 81.9%
Target pests: Powdery Mildew
For use in: Residential: Fruits & Fruit Trees, Herbs & Spices, Ornamentals, Roses and Vegetables
* See label for complete list
Application: 4 teaspoons per 2 gallons of water
* See label for complete application instructions
Pet safe: Yes, if used as directed on label
Special Features: - For Organic Gardening
- ORMI Listed
Shipping Weight: 0.50 lbs
Manufacturer: Monterey Lawn & Garden (Mfg. Number: LG 3270)
UPC: 022179102064
EPA Registration: 54705-10


Why Old Fashioned Fungicide?

The Bi-Carb Fungicide is called Old Fashioned because, if grandmother wished to control powdery mildew on her roses, she would mix up a solution of baking soda (sodium bicarbonate) and use it as a spray. In fact, many organic growers use this method until now. However, through our advanced technology, we have replaced the sodium with potassium since it is safer on the plant and breaks down into an essential plant nutrient for the same results.

What can I use Bi-Carb Old Fashioned Fungicide on?

There are numerous species on the label. Plants that are highly susceptible to getting powdery mildew are ornamentals such as roses, euonymus, and crape myrtle, vegetables such as squash, melons, cucumbers, pumpkins, peas, beans, beets, and Swiss chard. Small fruits and berries such as cranberries, strawberries and grapes. And fruit trees such as apple and pears.


Bi-Carb Old Fashioned Fungicide is a fungicide containing microencapsulated potassium bicarbonate as the active ingredient. Bi-Carb Old Fashioned Fungicide is a contact fungicide, so direct contact with the fungus organism is required for control. Bi-Carb Old Fashioned Fungicide disrupts the potassium ion balance in the fungus cell, causing the cell walls to collapse.


For residential use. Apply with a hand-held sprayer making sure to spray foliage thoroughly. Contact of the disease organisms is essential for control. Use a non-acidifying spreader/sticker such as Monterey-Nature’s Own Spray Helper. In addition, users can also use a non-phytotoxic crop oil.

RATE: Mix 4 teaspoons of Bi-Carb Old Fashioned Fungicide in 2 gallons of water to thoroughly cover foliage.

MIXING: Fill the spray tank 1/2 full with the required amount of water; add Bi-Carb Old Fashioned Fungicide slowly; then, continue filling with balance of water. Add the spreader/sticker and/or other products last. DO NOT allow mixture to stand. Use within 24 hours as Bi-Carb Old Fashioned Fungicide may lose its activity if left in the tank.

COMPATIBILITY: Bi-Carb Old Fashioned Fungicide is compatible with most crop protection products and nutrients. However, do not mix it with highly acidic products as the effectiveness of Bi-Carb Old Fashioned Fungicide may be compromised. Use of a buffering agent for acidification of a mixture can decrease the effectiveness of Bi-Carb Old Fashioned Fungicide. If compatibility is in question, use the compatibility jar test before mixing a whole tank. Because of the wide variety of possible combinations that can be encountered, observe all precautions and limitations on the label of all products used in mixtures.

TIMING: Begin application at first sign of disease. Repeat applications as new growth or infection occurs or as favorable disease conditions continue. Use in an Integrated Pest Management rotation program at 7-10 day intervals with other effective fungicides for resistance mangement. Apply Bi-Carb Old Fashioned Fungicide up to the day before harvest for all labeled uses. For post-harvest, apply Bi-Carb Old Fashioned Fungicide to remaining foliage to decrease overwintering inoculum.

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