Can you tell what's happened to this mandevilla? it looked fine, and then about 10 days ago started dropping leaves and stopped making flower buds. The leaf dropping has gotten worse the past 2 days. Is this over-watering, or disease, or insects? Thank you.
Carroll County Maryland
Hi - Mandevilla is susceptible to some fungal diseases but we do not see symptoms that are indicative of an apparent disease or pest problem on yours. The pattern of browning suggests a problem in the root system -- possibly from overwatering. Was this recently planted or have you had it in this container for some time? Did you have the plant indoors in the winter and recently moved it outside? Does the container have a hole at the bottom that allows for excess water to drain out?
I would recommend to prune out the browned leaves and stems, and be mindful about watering. Mandevilla is sensitive to overwatering. Rather than watering on a set schedule, it is best to feel the soil by pushing a finger down into it to check the moisture. If it feels dry, crumbly, hot, then water thoroughly, but if you still feel some dampness, hold back on watering. In very hot weather, you may need to check on the soil moisture every day.