I will have to look out for it at the garden centres.
I would recommend NOT to go this route I would suggest you get in touch with your local Chrysanthemum society.
This way you are likely to find that most growers will only be too pleased to sell you a few.
My reason for this is: garden centre stuff is often diseased (White Rust) as I know to my disgust this year when I bought some 'charm' varieties from Aldi/Lidl, they were blathered in it.
I have even noticed that some of the main mail order companies are importing from Holland these days as opposed to propagating their own stock, so this increases the risk also.
So buying clean stock is a bit of a minefield these days!
Societies stuff is usually selected stock and disease free.
Hopefully my stock is not contaminated particularly as I do not grow as many now.
I usually buy my new stock (if needed) at the Society stand at Harrogate Spring Show.
ps Glad you like my jigsaw stock.