I have no experience of growing them in a climate such as yours but have quite a bit of experience in the UK as it was once one of my ' Hobby' plants.

I would say that now is a fine time possibly where you are but here in the UK I would have started in Jan / Feb.

Do you have lots of basal growth around the base of your plants?

The reason I am asking is; what's going through my mind is to take ' Irishmen's cuttings' this is where you would dig up the plant ( assuming it is in they are in the ground) tear away rooted basal growth and pot these up as cuttings.

This method would save going through the rooting process thus catching up with us in the UK.

I have written a comprehensive article taken from my diaries over the years which might help you.( see link below)

I can't be more specific than that, simply because, I don't know what type you are growing or the state the stools are in now ( a picture would help)

Have a read of this and get back to us......Tg

http://www.thegardenersalmanac.co.uk/Data/Chrysanthemum/Chrysanthemum.htm