Does anyone here know where I could purchase some heirloom mum plants through mail order or over the internet?
Most specialty mum companies I know sell mum slips which are rooted but small and have to be grown on to get to mature size.
I don't know your weather that well but here in the nort h in zone 5 we need to get them in after frost in the Spring and most varieties need to be pinched back around the fourth of July and then allowed to bush out for Fall mums.
I would imagine you'd need to know the variety names for the ones you're interested in in order to be able to find those specififc varieties at those specialy companies.
Do you know which ones you want?
Try selectseeds.com. They specialize in antique and heirloom flower seeds. They list one heirloom mum. They seem to be sold out of it for this year but you can make a note for next year. The one they list does well in the South, they say.
Sarah, have you had any luck locating them?
Southern Living's September issue featured an article about heirloom mums that caught my eye. They didn't include a list of sources. Haven't tried emailing them yet, but my search on the internet didn't turn up much. Disappointing, because the ones they pictured were gorgeous!
I have some heirloom mums if you are still interested you can email me email@example.com