I am sorry for this delayed reply to your gardening question. The spring rush has brought a deluge of questions and we are working hard to catch up!
It is either due to dry soil conditions or a root problem such as nematodes. I suggest you dig up a plant or two with some roots and soil attached and take it to your County Extension Office for a diagnosis for nematodes.
Thanks for the question. Best wishes for a wonderful gardening season. Please stop in again soon!
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