It's a shared ice cream cone. You don't have to wait for February 14 to get or give that feeling. Just as you can have Christmas in July, you can make any day Valentine's Day. Flowers remind us of Mother Nature at her most lovely, which is always helpful when dealing with romance. Plants are lovely, but not nearly as romantic.
Flowers symbolize new life.
It's no wonder suitors give their loved ones flowers to show the blossoming of their love. Interestingly, flowers also symbolize purity and virginity. Specific flowers have specific meanings, as well. Though it's open to interpretation, here's a consensus of what certain flowers mean. Trust me, anything that works on the designated holiday works even better on a random day and is scads cheaper.