Q: My garden in San Diego is about three miles from the beach. We seem to have a regular breeze that keeps the air circulating. But I have a problem with mildew on bedding begonias, Iceland poppies, salvia and zinnias. How do large gardens, like Roger's Gardens and Sherman Library Gardens, avoid any sign of mildew on their lush displays--even though they're so close to the beach?
A: My own flower garden is a half-mile from the beach, and mildew can be a problem on the flowers you mention, especially late in the season when the days are shorter. I try to plant my flowers in sunny locations and avoid overhead watering. Since I turned off my overhead sprinklers and started using soaker hoses that seep water into the soil, mildew is greatly decreased.
If mildew does break out, I spray Funginex. In checking with Roger's Gardens in Newport Beach and Sherman Gardens in Corona del Mar, I learned that Funginex is sprayed at the first sign of mildew. Kathleen Sommer, horticulturalist at Rogers, also cautioned against excessive soil water. Letting plants dry out between watering decreases mildew.