Possible Clues:

• Self-reproach
• Rue raising sample of winter geraniums
• "A man has cause for ___ only when he sows and no one reaps": Charles Goodyear
• 'We ___ to inform you . . .'
• Facepalm emotion
• Feel sorry about welcome lacking energy
• Ruefulness
• Feel remorse having run over white bird
• Sad to say, no pubs in Petersburg
• Remorse for something done or left undone