Annie,..lots of people have problems growing Chrysanthemums where i live,..that is the supposed Autumn/Winter ones,..i have the feeling the Nurseries have just taken the young plants straight out of greenhouses,..they look good but the sudden change in temperature kills them within a month.
The Yellow ones i purchased for my neighbor were outside for over a month before i selected them and no sign of wilting.
One could be lucky and get plants used to the heat change,..or cuttings from established plants are nearly 100% successful