Common Leaf Spot
Ramularia grevilleana
4 host plants
Common leaf spot creates brown spots on foliage with concentric rings and light-colored centers. You see spotting develop in wet spring weather. The fungus spreads via water splash and wind. Manage through removing infected leaves, improving air circulation, and fungicide use.
Removing foliage after harvest reduces inoculum in the field. Mow leaves of June-bearing plants 0.5 inch above the crown after harvest.