Spring mums are sprouting, and it is time to perform maintenance and ensure gardens and flower beds bloom well into the Fall. When mums grow to the height of about six inches, one should cut them and start new plants from the trimmings. Taking the top three inches off your plant will force it to branch out and produce more blooms. Once the cuts have been made, place the trimmings in a moist potting soil. Make sure the soil holds moisture throughout this process. They should begin to take root within two weeks.