Vanderbilt University has a very nice site for looking at Valentine’s Day from Smart Energy and Environmentally Friendlier perspectives (http://news.vanderbilt.edu/2011/02/green-valentine/)
It gives some stats and also some substitutions.
Americans tend to go all out. For example:
• 198 million roses produced for Valentine’s Day in 2010 (Society of American Florists)
• 141 million Valentine’s Day cards exchanged each year - not including packaged kids’ Valentines for classroom exchanges (Hallmark) It's the second-largest holiday for giving greeting cards.
• $14.1 billion expected spending on traditional Valentine’s Day merchandise in 2010 (a survey conducted by the National Retail Federation)
Alternative suggestions include: sending an e-valentine, giving a potted plant, eat at a restaurant that uses locally grown foods.