Historical clue formulations

• Swiss ___ (salad green) — 2026-05-18
• Alternative to kale — 2025-10-05
• Swiss green — 2022-10-11
• Green vegetable — 2019-05-04
• Kale alternative — 2018-06-10
• Certain salad green — 2015-09-02
• Thick-veined vegetable — 2013-05-02
• Swiss ___ — 2012-08-16
• Leafy vegetable — 2012-07-02
• Leafy green — 2006-10-22
• Salad green — 2005-06-03
• Garden green — 2001-01-20
• Beet variety — 1997-08-03
• Swiss ___ (vegetable) — 1996-11-04
• Leaf vegetable — 1995-08-06