I see you found a source via a reply to your post at The Herb Forum. Sue

Mint? Go to the grocery store, buy a bunch of mint for a dollar or two. (Make sure it looks alive! Not wilted but vigorous.) take a 4" deep tray, fill with moist playsand (DO NOT MAKE MUD!...roots need oxygen). Pop pencil holes in the sand, drop in diagonally cut stems and cover with a humidity dome or a sealed clear plastic bag. Use sunlight or daylight artificials. No rooting hormone required. In 2-3 weeks you'll have more mint to transplant than you'll ever need. If you want the roots to get big...leave plants in the sand, remove dome and water with with a super diluted nutrient supplement like Masterblend or MiracleGro This technique will work with almost all fresh cut (perennia) herbs.

Loori - I have looked up 'Swiss mint' and it seems to be a variety of Mentha piperata - peppermint. In order to grow it successfully it is useful to think about what this plant's natural conditions would be. In its native habitats M piperata would obviously live outdoors with ample light. It likes moisture but not stagnant water. It is a perennial so it is designed by nature to die down in the winter and regrow from its roots in spring. In the UK it goes down to overwintering green stolons and does not completely disappear like M spicata. It is a European native and is happy in temperate and continental climates so is quite capable of enduring very low winter temperatures. Bearing all this in mind try to think of the best place you have for your plant. If you have a garden outside planting it in the soil would be best. If you only have a balcony I would put it out there. If the pot is likely to freeze through for any length of time I would wrap it in something insulating when frost is expected just in case. Although mint can be kept indoors in the winter it will shorten the life of the plant because it will get no winter rest and it will be struggling against poor light, overheating and probably too much water. I have a pot of mint outside my kitchen door and it is left out all winter. temps last winter went to -5C once or twice but that is unusual for here. 7c would not bother your mint at all. (Remember most people on this forum are in the US so when they say 0 degrees they are talking Fahrenheit ie VERY cold.)

Michael, are you sure of Fusarium and Verticillium being the problem? I ask b'c Fusarium does not exist where the ground freezes solidly in the winter. So it's a disease that's found primarily along the East Coast from maybe VA down to FL and along the Gulf Coast up to CA, roughly. And there are pockets of disease elsehwhere as well. Verticillium can be found either north or south, but I've seldom seen it decimate crops year after year as reported by others.''In my zone 5 area I think I've seen it twice in the last 20 years or so and then the plant outgrew the disease. But that's not to say that it can't be a bad actor for some folks plants from time to time. There are NO resistant varieties to ANY disease, only tolerance, which is different. And that includes the hybrids that have something like VFNT next to the variety name. Tolerance only gives maybe a couple of weeks extended time and can be of great use for the large commercial farmers who determine when to pick based on Brix concentrations, so not of great use to the home gardener. When folks do grafting they don't use an existing variety they use something called Maxifort rooting stock for grafting which have been developed with different tolerances to different systemic tomato diseases. I did a search here on grafting last night and found several threads about grafting using Maxifort rooting stock, but then didn't link to that here before I asked you about the diagnosis of what you now have. Would you mind sharing with us who made the diagnosis and what the symptoms are? Again, before you proceed it would be good to know the situation b'c of what I said about Fusarium and also b/c one has to rule out the most common tomato diserases, which are the foliage diseases, most of which do build up in the soil and can cause splashback reinfection from year to year. At another place where I psot there are many folks from Australia where selling grafted plants is quite common, but they don't seem to see any great improvement since again, no tomato plant is resistant to any disease, just tolerant. Carolyn