I purchased 4 bareroot angel trumpets In March 2016. They sprouted leaves and are 1-4 feet tall. Now I am noticing brown tips on all 4 and 1 started dropping leaves in July. I have not fertilized them yet because I am afraid to burn them off. They are in a pot. What am I doing wrong? Thank you for your help.
Make sure you are watering adequately in the warm weather.
Your plants need daily and even twice a day watering in warm weather.
Also make sure the soil is well draining, and that the roots are not standing in water.
These links will help you.