What is this substance and how do I remove or eliminate it from my gardenia plant?
White, Sticky ‘Cotton-Like’ Substance on Gardenia Plant
Certified GKH Gardening Expert
Gardenias are vulnerable to various insects including: Aphids, Mealy bugs, Scales, Spider Mites, Thrips, and Whiteflies. Many of these pests secrete a sticky substance known as honeydew. If it’s cotton-like in appearance, then most likely your problem is due to mealy bugs. Here is a link you may find helpful in treating this pest problem:
You can also try neem oil. Here is more information: https://www.gardeningknowhow.com/plant-problems/pests/pesticides/neem-oil-uses.htm