Today I felt like I was talking about plant diseases all day long. Fungal problems on oak leaves, bacterial issues on redbud leaves, root rot on rosemary and other herbs, redbud trees loosing huge branch portions, more fungus on St Augustine grass, rust on mealy blue sage. The excessive rain we have been enjoying is the main cause of most of these problems, along with high humidity between rain events so that nothing is drying out. But most of these issues are happening in yards with poorly draining chocolate or sandy loam soil. In some cases the problems are on older plants that are near the end of their lives anyway. I'm really pushing the use of areobic compost tea to help with these problems. It helps improve the soil by encouraging soil microbial life. The little microbes move around in the soil and they make heavy, gummy clay soil more pourous so water can drain out faster and more air can get to the roots. This makes for a healthier soil system and happier plants that are more disease resistant. Anyway it is a bummer that this year and last year were both weirdly rainy and caused all kinds of fungal growth and bacterial diseases. In most cases it is most economical to remive ailing plants and replace them with something different. Make sure you add lots of compost to the soil when you plant something new to help improve drainage.
Pink skullcap was one of the plants that fell ill this year and last year, especially older, unkempt plants like the one in this photo. Symptoms of root rot include entire branches dying suddenly, and the dead branches pull off the plant very easily.