We have coneflowers and they got tall, budded, and before they bloomed, the heads started to droop. The leaves started to wilt and then the stalk died. Half of the bush is dying and half is ok (for now). Can you help? What is going on with them and what we can do to fix the problem?
This article may help pinpoint the problem: https://www.gardeningknowhow.com/ornamental/flowers/coneflower/coneflower-problems.htm
For most pest or fungal issues, neem oil is effective. Here is more info: https://www.gardeningknowhow.com/problems/pests/neem-oil-uses.htm