torenia

Question

My Torenia appears to wilt and feels a bit tacky.

Answer 1

It is likely being affected by insect pests - perhaps aphids or another sap-sucking insect. The stickiness is from the honeydew these pests leave behind. I recommend treating the plant with Neem oil, which will help take care of these pests and many others. Here is more information: https://www.gardeningknowhow.com/problems/pests/neem-oil-uses.htm
https://www.gardeningknowhow.com/plant-problems/pests/homemade-aphid-control-a-natural-way-to-kill-aphids.htm