Care of Container Grown Mums. After the mums wilt be sure to cut off the flowers this will encourage more bloom. 3 Tips To Keep Your Mums Blooming Throughout Autumn Mums Blooms Autumn Fall Plant Container Water Location Buddi Fall Plants Mums Flowers Garden Mum After the first week one inch of water a week will do just fine. How to take care of mums outdoors in pot . In many cases it is not the cold that kills mums but rather the ice that forms around the roots if theyre planted in soil that collects water. The next step in winter care for mums is to properly insulate them in the fall. If the temperature doesnt drop below 32F in the winter you can leave your potted mums outdoors. The steps for wintering mums start when you plant them. Once potted mums have endured a hard freeze their chances for surviving winter are slim. It also serves as a good reminder in the spring to search for any healthy new root growth under the ground. If the weathers very hot and the rai...