Impatiens are being attacked
My beautiful bed of these flowers is a disaster. Something is stripping the leaves and flowers, leaving these long unsightly stems. I have dug into the soil and there is no evidence of slugs. Whatever it is, it has moved through the entire bed of over 250 plants.
Certified GKH Gardening Expert
I would venture to guess that either slugs or cutworms are the culprit in question. Slugs normally feed at night, which is why you wouldn't see them. Neem oil may help with cutworms, as well as most other insect pests. Here is more information: https://www.gardeningknowhow.com/plant-problems/pests/facts-about-slugs-and-how-to-kill-garden-slugs.htm
Try spraying with greenfly treatment and keep the slug pellets down if you live in wet area. Good luck