Invitations

• Slip pressed and dried lilacs into your birthday invitations; purchase invitations bordered with lilac flowers. Alternatively, buy clear stationery stickers with small dried lilac blooms inside them. If you have artistic talent, paint lilacs on the invitation in a sheer layer of pastel color, and write or print the invitation across the top, once it's completely dry.
  
  

Decorations

• If lilacs aren't in season for your birthday celebration, use cloth lilacs or actual freeze-dried lilacs that are still fragrant. Buy artificial lilacs and use them as a centerpiece for the birthday table, preferably in an antique vase or metal watering can. Use a white linen tablecloth rimmed in lace or tatting and use antique plates, preferably painted with lilacs. If your party will be held in the evening, burn lilac-scented candles in the room.
  
  

Refreshments

• Lilac blooms are edible! Candy them and arrange in a riotous bouquet atop your cake, place a sprig or two on your cupcakes or use them as a plate garnish for finger foods. Alternatively, shape your cake to look like a spring hat or watering can and place a bowl of fresh or freeze-dried lilacs on the top. Bake sugar cookies topped with lavender icing in the shape of lilac blossoms, or simply use candied lilacs. Place candied lilacs inside a tray of ice cubes and serve the frozen cubes in fruit punch.
  
  

Favors

• Give your guests lilac-themed favors, such as clear bookmarks with pressed lilacs inside, lilac-scented candles or fragrance, handkerchiefs or other linens with embroidered lilacs or stationery with a lilac theme. If your guests are gardeners, give them small clay pots with lilac shoots in the soil or a gardening book about the different varieties of lilacs. Alternate possibilities might include room fragrance, drawer liners or spring potpourri made from lilacs.