A Christmas riddle is:
 
Q: What did one Christmas tree say to another?
A: Lighten up!
 
“What did the Christmas tree say to the string of bulbs when they were sad? Lighten up! #christmas #jokes” was posted on Twitter by Mirth in a Box on December 7, 2015. “What did the Christmas tree say to the light bulb when it was sad? Lighten up!” was posted on Twitter by Jokes For Christmas on December 8, 2015. “What did the Christmas tree say to the light bulb when it was sad? Lighten up! #badcrackerjoke” was posted on Twitter by Sustainable Hive on December 25, 2015.
 
“What did one Christmas tree say to another? Lighten up!” was posted on Twitter by 💋💜💞Tipper.30💞💜💋 on December 1, 2020. “What did one Christmas tree say to another? Lighten up!” was posted on Twitter by Paul Ward on December 4, 2020. “What did one Christmas tree say to another ? Lighten up !!” was posted on Twitter by MBTA Transit Policeon December 12, 2020.
   
     
Twitter
Mirth in a Box
@MirthinaBox
What did the Christmas tree say to the string of bulbs when they were sad? Lighten up! #christmas #jokes
9:55 AM · Dec 7, 2015
   
Twitter
Jokes For Christmas
@jokes4christmas
Christmas Jokes 2015 - What did the Christmas tree say to the light bulb when it was sad?
Lighten up!
#jokesforchristmas
#christmasjokes
#ha
8:31 PM · Dec 8, 2015
   
Twitter
Sustainable Hive
@SustHive
What did the Christmas tree say to the light bulb when it was sad?
Lighten up! #badcrackerjoke
9:25 AM · Dec 25, 2015
 
Twitter
Jokes For Christmas
@jokes4christmas
Joke For Christmas
What did the Christmas tree say to the light bulb when it was sad?
  Lighten up!
#JokesforChristmas
#ChristmasJokes
#lol
9:17 PM · Nov 2, 2016
       
Twitter
Bob Byatt
@coachbyatt
What did the Christmas tree say to the light bulb when it was sad?
Lighten up!
7:02 AM · Dec 15, 2019
   
Twitter
💋💜💞Tipper.30💞💜💋
@MtbVicky
Replying to
@blackfriarsbake
What did one Christmas tree say to another? Lighten up!
🎈🎈Following and retweeted 🎈🎈
⭐⭐Amazing Competition⭐⭐
@ericawylie6
@MiFields87
@NESS1E
@nicola_b27
@tweenandscreen
9:33 AM · Dec 1, 2020
   
Twitter
Paul Ward
@pauldward
@TeresaKirk@kerry_skdjlea
Day 4….it’s Friday! 👍👍
What did one Christmas tree say to another? Lighten up!
#ChristmasJokes
2:15 AM · Dec 4, 2020
   
Twitter
MBTA Transit Police
@MBTATransitPD
Saturday Humor: What goes “Oh Oh Oh” ? Santa walking backwards.
Bonus: What did one Christmas tree say to another ? Lighten up !!
8:15 AM · Dec 12, 2020
   
Twitter
Space Rose
@xxspacerose
What did one Christmas tree say to another? Lighten up!
11:07 AM · Dec 14, 2020
   
Twitter
FALLINTOTALK
@fallintotalk
- What did one Christmas tree say to another?
- Lighten up!
Merry Christmas!
#MerryChristmas #fallintotalk #English #christmasjokes
5:38 AM · Dec 25, 2020
 
Yahoo! Life 
65 Jolly Christmas Jokes to Keep the Whole Family Laughing All Season Long
Larry Stansbury, Hannah Jeon
December 1, 2021
(...)
What did one Christmas tree say to another? Lighten up!
   
18 December 2021, Southern Highland News ( Bowral, NSW), “Crackin’ jokes and puns to whip out at Christmas time,” pg. ?:
What did one Christmas tree say to another?
Lighten up!
   
Best Life
126 Christmas Jokes That’ll Make You Fa-La-La-Laugh Out Loud
By BEST LIFE EDITORS
NOVEMBER 22, 2022
(...)
42. What did one Christmas tree say to another? Lighten up!
 
Good Housekeeping
86 Funny Christmas Jokes That Are Tree-mendously Hilarious
Score some laughs with these punny one-liners and hilariously savage quips.
BY HANNAH JEON AND ANNIE O’SULLIVAN UPDATED: DEC 23, 2022
(...)
What did one Christmas tree say to another? Lighten up!