Hi Jim,

Thanks for your interesting questions! Hopefully we can get to the bottom of it.

First, can you let us know why you were applying neem oil in the first place? Did you apply it because the leaves were sticky? Or were there insects on the tree? Or maybe signs of fungus? Or something else? Some insects, such as aphids, release a sticky substance called "honeydew," which could be what you are describing. Aphids are usually found clustered around new plant growth, and can often be flicked off by hand without pesticides.

Next, what form of neem oil are you applying? Did it come from a ready-to-use bottle or was it a concentrate you mixed with something else? Some neem oil forms are mixed with dish soap, which could also result in a sticky residue.

The most important thing when applying pesticides (even organic products like neem oil) is to follow the instructions on the label. They should explain how to apply the product to the plant and how often to do so. Many labels recommend applying neem oil to the tops and bottoms of all affected leaves.

As for your question about watering, generally you want to keep the soil evenly moist. Depending on the type of sunlight, size of the pot, and dryness of the air, keeping the soil evenly moist may require some trial and error. Watering once a week is a good timeline, but if you find that the soil is still soggy a week later, you may be saturating too much. If you are unsure whether the soil is still moist, try testing by sticking your pinky finger an inch or two into the soil. Here is some general information on indoor ficus care:

https://extension.umaine.edu/gardening/2022/01/04/inside-care-for-ficus/

Please let us know if you have more information that can help us solve this riddle. Photos are helpful!

Best,

Andrew