Observing Bulbs
Part II: The Mystery Inside

Overview: If you've done Part 1 of this lesson, you've carefully observed the outsides of the tools you'll use to gauge spring's arrival. What more can you discover by looking inside these precious packages?
What do you suppose we would find if we looked inside a tulip bulb?

Teacher Background: A bulb is an amazing container: a swollen underground stem that stores food energy and contains a miniature plant with flower, leaf, and root parts, all ready to spring forth when conditions are right. But don't reveal this to your students just yet; let them first make their own discoveries!

Laying the Groundwork
Ask, What will we find inside a tulip bulb? Accept all ideas and ask students to explain their thinking. Finally, invite the class to take a trip inside and see for themselves.


  1. Dissect bulbs. Give each group of 4 to 6 students a magnifying lens and a bulb. (Make sure these are extra bulbs and not the ones students will plant.) Slice each bulb in half lengthwise, from the pointed top down through the base of the bulb. If you have enough, also slice one horizontally for comparison or ask students how they want you to slice it.
  2. Draw and reflect. Pass out copies of the journal page, My Tulip Bulb: An Inside Peek. Tell the class that this may be their only chance to look inside a tulip bulb, so they should try to draw every detail they notice. Explain that each part of a living thing serves a role in survival.

    As students focus on specific parts of the bulb, have them think about the "why" (Why is this here?) and the "what" (What could it be?) behind each part they see. What
    new observations and ideas do they have when they look through the magnifying glass?
  3. Share ideas. As a class, discuss the different parts of the bulb students observed. Make a class chart like the one here (to the right).
  4. Compare ideas with what scientists say. Finally, explain that a tulip bulb contains all that's needed for a tulip plant to burst forth, grow, and flower when conditions are right in the spring. Give each small group a copy of the Parts of the Tulip diagram. Have them try to find the labeled parts on their own bulbs if they haven't already. Compare what they learn with the ideas on the class chart. What new questions do they have?

* Tulip bulbs to open up (1 per 4-6 students)
* Magnifying lenses
* Handout: Parts of the Tulip
* Journal page: My Tulip Bulb: An Inside Peek (pictured below)


WHAT we saw
WHY we think it's there
 WHAT it could be 
Things that look like rings of an onion To protect the tiny plant we think we see?  Not sure; leaves? 
Use a class chart to share your ideas

Parts of the Tulip
Click to Enlarge & Print


Discussion and Journaling Questions

  • Now that you've explored bulbs, inside and out, why do you think we're using them to track the greening of spring?
  • How do you think different bulb parts will change in the spring? What do you think will cause them to change?
  • Do you think the weight or size of a bulb will affect when or how it comes up and blooms in the spring? How? (Consider doing the Digging Deeper activity, below.)

Digging Deeper:
Using Bulb Observations to Make Predictions

Now that students understand that tulip bulbs will, in fact, grow into new plants, consider conducting this activity. Do this before you put the bulbs in the ground. It engages students in making predictions about how the size or weight of bulbs (explored in Part 1) might affect their growth in the spring.