Birthdays are a time to look over the events of the past year, celebrate life and set goals and wishes for the following annum - oft symbolized by the lighting and the blowing out of birthday cake candles. If you're lucky enough to be celebrating a spring birthday this year, you might consider planting those wishes instead for a tangible and effective emblem of growth.
You don't have to make this the main focus of your fete, but you can set aside a half hour or so for everyone to come outside and plant a wish. You can choose a selection of blooms or plants based on your own personal preferences or poll your guests to see what their favorite flowers are - either way, it'll be a meaningful moment for everyone involved.
To keep the spirit alive, offer guests plantable birthday party favors. Bloembox flower seeds make a wonderful addition to any goody bag and will enhance everyone's moods and environments once they bloom into full-grown plants. Be sure to pair with miniature flower pots that you and your guests can decorate.