Trolberg Winter Festival

The Trolberg Winter Festival is an annual festival held in the city of Trolberg to celebrate the blooming of the Sonstansil Tree; a rare event that only happens once a year. The tree blooms with glowing, orange flowers, that light up the entire tree.

Activities
The celebration shares a lot of similarities with Christmas. People like to decorate their homes with lights and plants, and gifts are exchanged during the blooming. In the days before the blooming, there is a market. The Sparrow Scouts sell their vegetable broth here.

It is also during the festival that Gryla and her Yule Lads hunt for naughty children.

The book "Hilda and the Time Worm" gives a more detailed schedule of the festival:
 * The buds of the Sonstansil tree appear on the first day of the Winter Festival
 * They open gradually during the three nights of the festival
 * When the last bud opens, the flowers begin to glow in the dark, an event known in Trolberg as the Big Glow
 * The morning after the Big Glow, everybody throws parties and gives presents.