After Christmas, retailers typically start marking down their Christmas decorations in order to make room for new items. The timing and extent of these sales can vary depending on the retailer and the specific items being sold. However, it is common for stores to have significant markdowns on Christmas decorations as early as January or February. Some stores may even start their sales as early as December 26th, while others may wait until the new year. It's a good idea to keep an eye on your favorite stores and online retailers to see when the markdowns begin and to take advantage of the best deals.