Answer: Your plants sound as though they are really stressed! Having them in the garden for 8 years means they are well established so the problems could be a result of an overly wet winter and early spring and perhaps soggy soil. Could be a fungal infection (it's difficult to diagnose without seeing the problem). I'd take a few of the affected leaves into a well staffed nursery or your Cooperative Extension office for on the spot diagnosis along with some advice on how to control the problem.
Good luck with your plants!
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