China Doll suddenly dropping leaves

(Question)

Hello
I have an indoor China Doll plant about 5 feet tall.its approx seven years old. Recently it started dropping leaves like crazy and I have no idea why. I have not changed anything in it’s care routine. I’m really struggling to find a solution as I love this plant and was proud of how healthy, green and full it was. Any suggestions would be greatly
appreciated.
I love east of Toronto and the plant gets indirect sun from a south facing window.

(Answer)

Thank you for contacting the Toronto Master gardeners with your inquiry.

China doll plant (Radermachera sinica) prefers at least 4-5 hours of bright, indirect light, moist well-drained soil and an ambient temperature of  18-24C. The main reason for leaf drop is change, a change in light, temperature, water or if repotted will cause massive leaf drop. During this heat wave has the temperature in your home increased? Is your plant in direct path of the cool breeze from an air conditioner? Is the soil drying out?

This plant prefers to be fertilized twice a month during it’s active growing period ( April-September). Use a standard 10-10-10- liquid fertilizer that’s diluted by half. Reduce fertilization during the winter months to every 6-8 weeks.

You might be interested in the following references: How to Care for China Doll Plant, China Doll Plant Care, China Doll Plant Growing Guide