first three chains of each ch-5 are considered a ch-3 sp to be used in Row 2. Also note that there is no long beginning chain to start the project. It starts with the first ch-5 and keeps adding length with each ch-5. Link of the pattern is below!
Christmas Tree Skirt
by Donna Mason-Svara
Christmas Tree Skirt [ FREE CROCHET PATTERN ] downloadable pattern is available here.