Coneflower foliage leaves and flower leaves’ edges turning black/brown and crisp, like it was roasted

Question

I just bought 2 coneflower plants 2 days ago. Right now they are in pots. We are having pretty bad summer for now. Out of the two, the one I kept in the front suddenly has many of its leaves turning black and super crisp. Even the edges of all the flowers are turning brown, like it may have been roasted by the sun. Its only on one side of the plant as far as the foliage goes, the one facing east. What could be wrong and how can I care for it better?

Answer 1

If they are in the same pots they came in, I would repot using potting mix. Or you can plant them in the ground. They may be root-bound and need to have the rootball loosened. If there are lots of encircling roots and you can’t straighten them, make 4 vertical slits through the outside roots. Then make an X in the bottom if roots are tight there. New plants need time to establish roots so they won’t die over winter. For this reason, get them in the ground within a month. Pick a time when the weather is reasonable and preferably cloudy. Any recently potted or planted coneflower is going to suffer transplant shock. Make sure to keep the plant in the shade for 3-5 days while the plant recovers. For in-ground plants, protect them from afternoon sun with an umbrella, large box or sheet attached to sticks. Potted plants may need water 1-2 times a day in hot weather. The more foliage, the more water loss there is. Only water when the soil is dry down an inch (pots) or down 2 inches (in-ground). Since blooming and forming seed is stressful and energy intensive for the plant, I would cut off all blooms while it is adjusting to its new environment. If water runs right through potting soil, the mix may contain sphagnum peat which is hard to rewet. Sink the entire pot in a bucket of warm water up over the pot rim for 15 minutes. Coneflowers are tough plants. I think yours will recover with some TLC.

Answer 2

Thanks for the response. They did fine in shade for a few days and then I planted them in our garden bed about 10 days ago. They were doing fine for a week and suddenly again they seem to be dying. The flowers are all wilted the leaves are dropping in number. Any advice on what could be wrong?

Answer 3

My coneflowers are giving up at this point in the season. Parts of them are black and leafless. Maybe it is shorter days that triggers this or a summer of flowering that wears them out. Keep them in morning sun only and well watered, although at this time of year, plants need less water than mid summer. Plant them in the ground as soon as reasonable given your weather issues.