Effects of Sodium Bicarbonate on Plant Growth

Sodium bicarbonate, commonly known as baking soda, is capable of preventing or treating diseases of plants when you use it correctly. Sodium bicarbonate, by itself or in combination with other ingredients, has shown effectiveness in controlling disease and boosting the growth of certain plants, according to the National Sustainable Agriculture Information Service.

Sodium Bicarbonate Knocks Out Fungal Diseases

When plants become the victims of fungal diseases such as powdery mildew, their growth can not only be stunted but they can die if the infection spreads and becomes severe. Powdery mildew appears as a fuzzy or sooty residue on plant leaves: it can be white, gray or black. To treat fungal diseases with baking soda, mix 1 tbsp. baking soda with 4 cups of water and ½ tsp. liquid dish soap. Spray your affected plant with this solution once every two weeks until all signs of the fungal disease are gone.

Acid-Loving Plants Will Benefit

From azaleas to tomatoes, numerous plants require soil that has a higher concentration of acidity than other types of soils, which can be neutral or alkaline. Alkaline soils have a pH reading above 7.0, while acidic soils measure below 6.0. Neutral soils range from 6.0 to 7.0 pH. To keep your acid-loving plants happy and growing to their maximum potential, water them with a solution of baking soda once a month. Mix about 1 tsp. baking soda to each quart of water and then water your plants with it.

Too Much Can Kill Some Plants

Because baking soda is a salt (the “sodium” in the official name tells us this), too much of it can be detrimental to the growth of some plants. When the soil in which a plant grows is too salty, it creates a toxic environment that is detrimental to some plants, such as orchids and tender leafy plants such as lettuce, according to Science Direct. The "California-Arizona Farm Press" reported in 1998 that bicarbonate present in western soils can not only plug drip system emitters, but is also responsible for tying up nutrients such as calcium, which causes lime to form. This condition causes blossom-end rot on tomatoes, tip burn on lettuce, brown pit in apples and interior brown spots in potatoes. It also causes crusting of soil surfaces, which inhibits plants’ ability to break through when they first germinate from seeds.