Target Grade Level / Age Range:

4th grade

Estimated Time:

Two 45-minute class periods


Students will understand how to take care of a Christmas tree at home and the science behind keeping the tree alive.


  • Celery with leaves still on
  • Scissors
  • Food coloring (red, blue, green, yellow or other colors)
  • Tall cups or jars, preferably clear
  • Observation worksheets, one per student
  • Paper towels
  • Magnifying glass
  • Poster Paper
  • Markers

Essential Files (maps, charts, pictures, or documents)


  • Xylem – the transportation of water and nutrients in vascular plants from the roots to the leaves (moving in one direction)
  • Phloem – a tissue in vascular plants that transports sucrose and other nutrients throughout the plant (moving both directions)
  • Transpiration -- the conversion of water from liquid to gas as it passes through plant stomata, small openings on the undersides of leaves of vascular plants.

Background – Agricultural Connections

Live Christmas trees need to be taken care of at home or else you may have needles all over the floor, a dead tree before Christmas or even worse – a tree up in flames. If the tree dries out, the needles will fall off and the tree could become susceptible to easily catching on fire. There are many ways that a drying tree can be prevented to make Christmastime enjoyable.

When you arrive at home cut an inch or two off of the bottom of the tree. Since cutting the tree at the Christmas tree farm or buying a pre-cut tree the pitch (similar to sap) has created a protective layer over the bottom of the tree. Cutting off the end allows for the pores to be opened back up and crucial water absorption to happen.

When choosing a spot to place the tree make sure that it is away from heat sources. If the tree is next to a heat source (like a radiator or heat vent) it will dry it out more quickly, possibly leading to a tree fire. The lower the temperature the better.

Then, fill your tree stand with water right away. Don’t let the water go below the fresh cut line or it will seal back up again. The tree stand should be able to hold over one gallon of water.

Interest Approach – Engagement

Tell your students that you are going to play an interactive game of Would-You-Rather. Have your students stand up. For each option point to one side of the room or the other. If a student agrees with that option, they will go to that side of the room. Use the PowerPoint to display the images and choices.

Would you rather?

  • Live at the beach or where it snows
  • Get a haircut or grow out your hair
  • Drink water or Sprite

Explain that just like you, Christmas trees have preferences. If they went to the wall for the drink water option, they like the same thing as Christmas trees!  



  1. Ask questions to get students thinking: What materials do you need to keep Christmas trees alive (hand saw, tree stand, water).
  2. Go to slide #6 on the PowerPoint. Once a student guesses a saw or you bring it up ask your students, “Why do you need a saw?”
  3. Explain that when you get home you must cut an inch or two from the bottom of the tree because the sap will create a film over the bottom of the tree. This sap could block the tree from absorbing any water. Cutting the tree allows for the pores to be reopened and the tree can absorb the water. Another object the students should guess is a tree stand and/or water, they go hand-in-hand. Ask again, “Why would you need a tree stand?” Explain that a tree stand helps the tree stand up straight and is what holds water. Place the tree stand away from any heat sources in your house. Trees like the cooler weather, if they are too hot, they can dry out and be more susceptible to catching on fire! A tree stand needs to be able to hold at least a quart of water per inch of stem diameter. Your tree will want to drink a lot of water. Making sure the tree has enough water is how to make it last longer. If you don’t, the needles will die and fall on the ground. If the tree trunk is four inches in diameter, the tree stand should hold four quarts, or one gallon, of water.
  4. Go to slide #7. Show with the pictures that the inside of the Christmas tree looks different than the outside. Point out on the second picture where on the trunk that the xylem and phloem vessels are located.
  5. Go to slide #8. Explain that this is an inside look of what the inside of the vessels looks like.
  6. Water is important for your tree. Water is what keeps the tree alive, your tree might even grow inside your house! Christmas trees drink water through a process called transpiration. Xylem and phloem are the structures to make this happen. Phloem moves food (sap and sugars) through the tree. Xylem is more important in that it moves water from the tree stand up the trunk and into the needles to keep the needles soft, pliable, and moist.
  7. Xylem vessels are specialized cells that let water flow one direction, up to the top of the tree. These vessels go to where the water is needed in the tree. Water will move in one direction from the roots (or the base of the trunk that is in the water) to the needles on the branches. A good way to remember the difference between phloem and xylem is that:
    1. Phloem (pronounced floam) lets water and nutrients FLOW through the vessels in any direction.
    2. Xylem vessels are hollow tubes that has water move up the plant (in one direction) from the soil to the leaves.
  8. Go to slide #9. Announce to the class that we will be doing an experiment to see how Christmas trees stay alive inside your house. If you would like a visual of how this experiment is done check out this link:
  9. Show your students a stalk of celery that you just tore off from the rest of the celery bunch. Explain that celery and Christmas trees are very similar. They both use xylem to drink water.
  10. Divide students into groups of 2-4 depending on the class size. Have them sit down at a table or desk in their groups.
  11. Just like how you need to cut off the end of your Christmas tree we need to do the same thing with our celery. You can either cut everyone’s celery up in the front of the classroom or pre-cut them and explain.
  12. Hand out a celery stalk and a half-filled water cup to each group.
  13. On the worksheet, instruct each student to write down any observations of the celery (what it looks like, smells like, etc.), and what they think is going to happen after they put it in the colored water.
  14. Go around to each group and put about 10 drops of food coloring in each cup. The darker the better.
  15. Have each group place their celery stalk in the water, stirring any of the dye into the water if needed.
  16. Each group must place their celery on a table. Explain to the students that they will make more observations the following day.
  17. NOTE: Go farther by asking students how temperature might affect water take up in the celery. How might students test this? Students could place some celery near a heat source and some in the refrigerator. Heat should increase the speed of water take up.
  18. Depending on the class either have them put away their worksheets or collect them for the following day before class ends.


  1. Before class pull up the PowerPoint presentation (slide #10) from the day before
  2. Ask questions to recap day 1 such as, “who can define xylem or phloem?” “What supplies do you need to take care of a Christmas tree at home?” For your last question ask, “What do you think your celery looks like today?”
  3. Have each student grab their cups of colored water and celery and bring it to their table. Hand out paper towels and magnifying glasses to each group. Instruct each student to take out their celery stick and put it on the paper towel. Go around to each group and cut or break their celery in half. This way they can see the xylem tubes a little easier.
  4. Instruct each student to either write or draw on the worksheet what they see.
  5. Ask students thought provoking questions to get them thinking more. “Where can you see the xylem and where can you see the phloem?” (Xylem is the main-colored part and phloem is just above it.) If students did not catch it the first time, ask them to look closely with a magnifying glass. “What are the stripes inside the celery?” (Those are the xylem tubes that the water travels to from the bottom to the leaves.)
  6. If there is any confusion go to slide #11 where everything is pointed out on pictures
  7. Clean up all experiment supplies and collect worksheets.
  8. To recap what students have learned and connect it to Christmas trees hand out poster paper and a box of markers to each group. Instruct each group to draw or write out how they would take care of their own Christmas tree. How does xylem and phloem keep the tree alive? How does access to water help the tree? Give the class 10-15 minutes to create their drawings.
  9. Once they are created have each group either hang up the posters on the wall or hold the posters up. Have each group explain what they drew and why they drew it. Ask questions to further thinking or to make sure they have a clear understanding. Ask questions such as, “Which way does xylem move in your tree?” “Can you define phloem?” “Where in your house should you place your tree?”

Did you know? (Ag facts)

  • It can take 6 to 8 years for a Christmas tree to grow full size
  • If watered and taken care of correctly, Christmas trees can last up to a month inside
  • 98% of all Christmas trees are grown on Christmas tree farms
  • There are around 100,000 people employed by the Christmas tree industry

Extension Activities

  • Try this same color experiment with a white carnation.
  • Have students research caring for other plants indoors. Have them compare and contrast lasting plants (with roots) versus temporary plants (cut flowers, with roots removed).
  • Have students further investigate how water moves through a tree. Here are some videos that might pique their interest.
    1. How do trees transport water?
    2. How can trees be taller than 10m?
    3. How do trees pump water?
    4. How trees bend the laws of physics?

Suggested Companion Resources



Madison Paine

Organization Affiliation

Iowa Agriculture Literacy Foundation

Agriculture Literacy Outcomes

  •  TI.3-5.e Identify the importance of natural resources (e.g., sun, soil, water, minerals) in farming

Iowa Core Standards

  • Science
    1. 4-LS1-1. Construct an argument that plants and animals have internal and external structures that function to support survival, growth, behavior, and reproduction.
  • English Language Arts
    1. W.4.7 Conduct short research projects that build knowledge through investigation of different aspects of a topic.