Shasta Daisy Diseases
I have an overgrown perennial garden, and some of the shasta daisy clumps have a problem with their lower leaves drying out and becoming dry and brittle. Is this a fungus or blight? Should I plant in this soil if such an issue exists?
This is likely just the aging of the plants.
Shasta Daisy is very forgiving and you can cut back and prune quite aggressively.
This is not indication of your the health of your soil. A soil test is always a good idea in a new garden or a garden that has been neglected.
This will help you take the guesswork out of fertilizing and soil amendments needed.