If your interested in keeping em out over winter heres some ideas depending how cold it gets thru winter. In Australia the climate is perfect for this setup as our winter days are about 15-20deg celcius, and our nights dont go below say 5 deg celcius.
You can use cheap Solar powered garden lights to stop plants from flowering, they automatically come on when the sunlight dims and are enough to prevent flowering.
And keep the moms in a mini greenhouse that has lots of heat absorbing stuff in it to release heat thru the night. Or use a wall o' water for each mum (look it up, supposedly protects plants to 20deg F or -7 deg C) and add some big rocks (prefably painted black) around the base of the mum inside the wall o' water, which will store extra heat for the cold nights.
If you winter days are really cold, wall o' water/greenhouse might not warm up enough to keep the plants warm thru the night tho.