My Princess palms were damaged by frost. Someone told me to feed them sugar. Will this help, and how much do I use? Is there something else that might help?
This cold has damaged many plants this year. These articles will help you:
https://www.gardeningknowhow.com/plant-problems/environmental/how-to-tell-if-a-plant-is-dead-and-how-to-recover-an-almost-dead-plant.htm
https://www.gardeningknowhow.com/plant-problems/environmental/tips-for-saving-cold-damaged-plants.htm
Sugar will not help. I would use a balanced fertilizer on the plants. If the trunk is still alive, it will recover.