mint is such an invasive runner.. that i would simply dig up a piece in spring.. and move it where you want it ...

and by the end of summer.. it will have outgrown your spot.. lol ..

i simply would not bother with rooting ... especially since you say your friend has a large patch ...'

which is saying.. you are in a box.. look outside your box ..

ken

ps: actually.. at the friends house. i would simply grab a bunch [with permission of course] ... and literally rip them from the earth ... throw them in the trunk.. and within a day or two plant them ... most mint.. you couldnt kill if you wanted to .. lol ..

pps: and its not that you cant root it.. its just that that is the hard way to do it.. with mint ...

This post was edited by ken_adrian on Sun, Dec 30, 12 at 11:51

Your post does not indicate where you garden. For most of us mint in the garden is an invasive pest and should only be grown in a container. It multiplies by underground stolons which creep all through the garden. The easiest way to start a new plant is to pullup a rooted piece of stolon and plant it. Al

What they ^ said mostly, but without knowing where you are or what type of mint you are dealing with, multiple factors are unknown. Some types of mint are native to various places in the US, so they would certainly not be invasive! Some non-native mints are invasive, while others are not. In some areas, some mints can be significantly environmentally damaging (invasive). Some gardeners may mistakenly think that by confining the growth of their invasive mints, the invasiveness is not a problem, but that is completely untrue. Invasive mints will reseed into areas, potentially quite a ways from the original infestation.

The easiness of propagation also varies quite a bit with different mint species and types. Unfortunately, some of the natives are a lot harder to propagate than the more commonly grown garden types of mint. I get the feeling that your friend's giant patch is not one of the harder types to propagate, or one of the natives, but that's just a hunch.