Historical clue formulations

• Plant with a heart — 2013-09-10
• Food with a heart — 2011-05-11
• Something you might want to get to the heart of? — 2008-07-17
• It may have a good heart — 1995-04-29
• Salad ingredient — 1994-04-19
• Heart of the grocery? — 1994-03-15