Powdery Mildew and Apple Scab - Sodium Bicarbonate

The Sodium Bicarbonate used by gardeners is no different from the household baking soda favoured by our grandmothers. It is a traditional and natural product with many uses in organic gardening, particularly for combating fungal diseases such as powdery mildew and apple scab. This fungicide acts preventively, and the first symptoms appear as soon as they appear, both in vegetable gardens and in orchards and ornamental gardens. After dissolving in water, baking soda is sprayed on plants from spring to autumn at a frequency that will be adjusted according to the humidity of the climate. Since January 2019, it has been approved for use in Organic Agriculture.

Sodium Bicarbonate, or Sodium Hydrogen Carbonate, is a white powder soluble in water. Its chemical formula is NaHCO_3. In the garden, it has many uses:

- It is an anti-powdery mildew agent with a fungistatic action. It acts on contact, preventively and as soon as the first symptoms appear, by increasing the pH and modifying the osmotic pressure on the surface of the leaves, thus limiting the ability of fungi, which thrive in acidic environments, to develop. This compound is mainly effective against powdery mildew on ornamental plants, vines, root vegetables, apple scab, and rust. Sodium bicarbonate is helpful against mould development during storage after harvest: apples, pears, cherries, currants, blueberries, cranberries, and lingonberries.

- It can also raise the pH of overly acidic soil: bury a few pinches of baking soda and water and then test the pH of the soil again until it is satisfactory.

- It is believed to have a repellent effect on specific pests.

Sodium bicarbonate is biodegradable and is not toxic to the environment or health.

Instructions: use from April to September

- Dissolve 3 to 10g / litre of water
- Spray on leaves as soon as the first symptoms appear or as a preventive measure
- Apply preventively every 15 days
- Repeat the application every ten days, especially after rainfall