Hi. My 6-foot-tall false aralia (indoor) had a mild infestation of soft scale that I treated first by dotting the individual bugs with alcohol on a Q-tip and a few weeks later with an overall spray of horticultural oil. Now the plant is dropping leaves like mad. Could the horticultural oil be to blame? Thank you.

Some plants can be more sensitive than others to horticultural oils.

Do you know what was in in it?
I'm reading some are better for dormant and mature leaves, others for when they are actively growing.

Anything else change?

Lighting, watering, temperature, humidity?

Getting a lot of heat here finally and watering most of my plants 2-3 times per week instead of 1-2.

Thank you for your reply. This product claims to be safe for both. The recommended application rate (tablespoons : water) is 2.5-5 : 1. I mixed it at at a ratio of 4 : 1, so maybe I overdid it. I have had the plant for several years, and it seemed quite healthy. The appearance of honeydew sap alerted me to the scale. Infestation seemed light. Any advice for what to do next? I plan to try to hose off as much of the oil as I can. Thanks.

And no, nothing else changed. Thanks.

P.S. I also made sure to seal up the pot so the oil would not reach the soil.

Did it help with the scales at least?

I'd trim off the dying leaves (saves a bit of plant energy), wipe the good leaves off a couple more times, and lower the lighting a bit. Location change, draw the curtains, add a sheet for a few days...

Then just be observant and patient.

Thanks. Yes, the scale seems to be gone. But I think it was overkill, literally. Lesson learned.