[Ice]

It's totally illegal of course and extremely anti social but I know someone that planted horseradish in a farmers field.  He planted it at the edge behind a barn so it could be mistaken for a weed.  Oh, and easily found.

[Jilly Pickles]

That's not horseradish, It;s the TRIFFIDS

[egg]

I am really pleased mine is in a pot AND I think I may have killed it but I will have a look when it gets a bit warmer!

[viettaclark]

Beware of the amazing green manure comfrey as well! It's another plant with a long tap root which grows if you leave just a tiny root piece in the soil!!! Don't let it flower and seed or you might get comfrey-ied!