My indoor gardenia has recently acquired some powdery "stuff" on the stems of newer leaves. Is this something I should be concerned about? The substance is similar to dust.
Certified GKH Gardening Expert
This is powdery mildew, which is caused by a fungus. Oftentimes, neem oil can help. Here is more information: https://www.gardeningknowhow.com/plant-problems/disease/get-the-cure-for-powdery-mildew.htm
Could it be pollen from blooms? Could it be mealybugs? A more detailed description would help. This link might answer questions for you: https://www.gardeningknowhow.com/ornamental/flowers/gardenia/gardenia-pests.htm