REGROW ROMAINE LETTUCE: Leave a few inches from the bottom of the heart when chopping up. Trim off the outer leaves of your starter heart, since they'll turn brown. Place in about a half-inch water. Change water every day or so, and let them get some light. Let it grow for a while before enough to harvest and start the process over again. If you want, you can even take the newly-sprouted hearts and plant them right in the ground.