| I am trying to grow Burpee's old fashioned mix zinnias. I am having problems with the leaves drying up, and getting brown splotches. I read your FAQ, but had already been attempting to treat them for what I thought was powdery mildew. 1 teaspoon of baking soda per quart of water sprayed on the leaves. Big mistake? Many thanks Richard Peterson |
| I don't think you've harmed your zinnia's with baking soda and water, but it sounds like you've figured out that blotches are not powdery mildew, but another type of disease. Powdery mildew shows up as a whitish coating on the leaves. Brown blotches sound more like Botrytis and a good garden fungicide should fix the problem. Be sure to rinse away any baking soda residue before spraying your plants with a fungicide. To avoid problems in the future, give your zinnia's full sunshine and plenty of elbow room to encourage good air circulation all around the plants. |
