Possible Clues:

• Yuletide tree, typically
• Where foliage remains throughout the year
• Say Olive is always colourful
• No fall in fall
• The foliage that doesn't change colour
• Never experienced, unlike 23 down
• Being always so inexperienced, never leaves off
• Never experienced in forestry
• Never leaves off advertising such growth
• Despite the title, 'Falling Leaves' is still a popular song