Q: On your radio show you mentioned mixing hydrated lime with water and adding salt to create a paint for trees. I bought a bag of powdered lime, which a garden center employee said I could mix with water. I did so and only a small portion dissolved. What am I doing wrong?
A: Garden centers usually carry two kinds of lime: garden lime (calcium carbonate) and hydrated lime (calcium hydroxide). Garden lime is used to slowly raise the pH of soil. Hydrated lime does the same thing but it works much faster and is very caustic. The whitewash recipe I mentioned calls for hydrated lime. I often see it sold in five-pound bags. To make whitewash, mix five pounds of hydrated lime with six pints lukewarm water. In a separate container mix one pound of salt with one pint of warm water. Let both mixtures sit for a day, stirring occasionally. Add the salt water to the lime mixture and stir well. Add powdered pigment for coloring if desired. Store tightly covered. Of course, you could accomplish the same result with white latex paint on your trees.