Historical clue formulations

• Windowside perches — 2026-09-23
• Prime bird-watching spots for indoor cats — 2022-12-19
• Spots for window boxes — 2021-09-05
• Perches for houseplants — 2020-11-27
• Places to put potted plants — 2019-08-27
• Places for small herb gardens — 2018-11-23
• Places to cool it? — 2017-08-12
• Window ledges — 2015-08-17
• Places to cool pies — 2011-04-18
• Framework components — 2009-09-04
• Sash supporters — 2009-08-29
• Places for dust to collect — 2008-09-19
• Grammy and Emmy-winning soprano — 2007-12-23
• See 21-Across — 2007-08-01
• Places to set geraniums — 2004-07-10
• Red-haired soprano — 2004-01-22
• Potted plant sites — 2003-07-10
• Met star Beverly — 2001-10-17
• Window bases — 2001-06-05
• Places for plants — 1998-11-29
• Noted coloratura — 1997-02-08