I copied this for you..
Although baking soda helps plants in various ways, it is a salt, and too much salt hurts plants in two ways. It can clog plant tissue cells so that plants take up less water than normal, causing them to lose energy, wilt and drop leaves. Also, too much salt can accumulate in plants and poison them; the condition is called "ion toxicity," and it causes plants' leaf edges to turn brown and appear burned. Baking soda should be used sparingly to avoid both issues.
Potting Soil
Baking soda is naturally alkaline. Although it does not lower the acidity of soil as well as lime, which is used for soil in large areas such as lawns, a small amount of baking soda mixed into potting soil can neutralize the soil's acidity that is detrimental to sensitive houseplants. Thoroughly mix 4 tablespoons of baking soda with 1 quart of lukewarm or room-temperature water, and apply the mixture one time -- either when the potting soil is first poured into a planting container or immediately after a plant is placed in the soil. Avoid overwatering a plant with the mixture because its roots should not sit in a puddle.
Powdery Mildew
Powdery mildew is a fungal disease appearing as a dusty white or gray coating on plant leaves. Because it limits photosynthesis, affected plants do not grow properly and eventually become deformed or wither. At the first sign of powdery mildew on a houseplant, mix 4 teaspoons of baking soda into 1 gallon of room-temperature or lukewarm water, and spray the mixture on the houseplant's leaves. Cover the leaves with a fine mist of the mixture rather than saturate them. Watch the affected plant closely, and spray it daily with the mixture if necessary. Severely affected leaves or stems can be removed and the remaining portions of the plant sprayed to save them.
it's turned into a beast going to have weed for years .