Here's a Good Thing that's perfect for St. Patrick's Day.
Tools and Materials
White carnations
Green food coloring
Vase
Scissors
Coloring Carnations How-To
1. Mix food coloring with water according to the directions on the food-coloring package, making sure the water reaches a dark, rich shade of green. Fill vase with this mixture.
2. Cut ends of carnation stems under running water and place the carnations into your vase overnight. The flowers will soak up the food coloring through the stem, resulting in vibrant green petals.
Resources
For more Irish-inspired ideas, check out our St. Patrick's Day photo gallery.
Coloring Carnations
Perfect for St. Patrick's Day. For more Irish-inspired ideas, check out our photo gallery.
The Martha Stewart Show, March 2009

I tried cutting the stems straight across, as described above, and whittling them at an angle, as M. Stewart suggested in the video. The results were the same shade of (lovely) green, so save yourself the trouble and just trim the stems as you would normally.
The kids will love this Leprechaun magic. Change the color of the dye for different holidays or just for fun. The carnations have changed red after Santa Claus' visit. Use the leftover Easter Egg dye for a bouquet of many colors. The carnations have changed color after the Easter Bunny visit.