I have 2 Joe Pye Weeds that I've had in this spot for 3 years. This year, one of them (they are growing side by side) looks terrible (yellow) and is stunted. I checked and don't see any obvious problem (like voles or insects). But I saw that the stems were turning brown/black from the base and working their way up - dying. Then the upper stems would break (I guess from no vascular activity).
Any ideas? This picture is of better days: last year.
thanks
