Question
I have been reading an answer you gave on controling powdery mildew on crape Myrtle trees. It mentions using the horticultural oil, baking soda formula. Can you specify this formula for me? We live in S GA and the mildew is a major problem. Thank you.

Answer
Hi Sharon,
Thanx for your question.

Mix 4 teaspoons (about 1 rounded tablespoon) of baking soda and 1 tablespoon of horticultural oil into one gallon of water. Spray lightly on foliage of plants afflicted with black spot, powdery mildew, brown patch and other fungal diseases. Avoid over-using or pouring on the soil. Potassium bicarbonate is a good substitute for baking soda. Citrus oil and molasses can be used instead of horticultural oil.


I hope this helps.
Tom