The Cedar of Lebanon (2013). Photo from Mormon Newsroom.
2. The first year of the Temple Square lights, arborist J. Leland Behunin spent six weeks of solo work to hang 40,000 lights--he didn't even have a ladder. An estimated 15,000 people came for the first lighting ceremony on December 9, 1965.
3. The well-known cedar of Lebanon,* one of the largest trees on Temple Square, boasts 75,000 red lights, but is only lighted every other year. (This year, 2014, is an off year.) This is done because each year it's wrapped, the delicate old tree gets needles and limbs knocked off during the wrapping and unwrapping process.
*Brought to Temple Square as a seedling by a woman who had come back from a trip to Lebanon, the tree was given to the head gardener and planted near the east gate. Seventy-five years later it stands at 70 feet tall.
4. Since 2009, the lights on Temple Square have been changing from incandescent lights to LED. The LED lights save on energy and money, consuming a fraction of the electricity that the incandescent lights would, and they are easier to maintain. They're also better for the trees because they don't produce as much heat as incandescent lights--which means less damage to the trees' structure and less bugs and disease.
5. The color theme of the lights is chosen to remind people of the Savior (the Light of the World)--not necessarily to remind them about Christmas. Jennifer Udy, a temple square gardener,explains that the temple lights are meant to be “in harmony with each other and with the Temple Square spirit.”