Q.Coreopsis Bubs Never Open
I have two coreopsis plants in my front yard. The foliage is lush and healthy and there are many buds. But they turn dark in the center and never open. The other plants in the garden, agastache, gaillardia, fleabane, azalea, coneflower, creeping thyme, and dianthus are all doing very well. What could the trouble be?
Certified GKH Gardening Expert
Unfortunately, your photos did not come through. I am unable to assess the damage. It could be that there is a lack of phosphorus or potassium in the soil, though. If the green growth is lush, but the flowering is not what it should be, this would be my first suspect.
These articles will help you to test your soil:
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/testing-soil.htm
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/soil-ph-plants.htm
This article will help you to care for the flower:
https://www.gardeningknowhow.com/ornamental/flowers/coreopsis/growing-coreopsis-flowers.htm