We grow common mint for mojitos using a plastic window-box about 1 1/2 to 2 feet long. It has a water
tray underneath to keep dirty water
from dripping everywhere. On light sailing days it sits on the cabin
top, windy days inside the dodger
, and very bad days and at night offshore
down below aside the main salon
table. I start the window box a month or so before we leave for the summer so it's ready to use on the first evening anchored. The mint has always made it through the whole summer (2-2 1/2 months.) There's nothing like a fresh mojito at sundown!