SAFE INSECT SPRAY
We bring in our hibiscus trees every year and have a "greenhouse" in our basement. However, by February, they are usually covered with aphids despite our spraying them very heavily before we bring them in. I was told years ago by you that a safe spray can be made using Ivory dish liquid and water. However, I have misplaced the instructions. Please let me know the dishwasher liquid-to-water ratio. Thank you.
Howard County Maryland
We cannot recommend a homemade remedy for insecticidal soap as it may be phytotoxic to the foliage. We recommend using an insecticidal soap specifically formulated for plants. Please read and follow directions for use.