What's Happening Underground?
Bulb Life Cycles

Teacher Background
Ever wonder what is happening to your tulip bulb under the ground? Explore the life cycle of the tulip bulb. Start in late fall to take a closer look. Predict what your bulbs will look like, then dig up one or more bulbs from the garden and explore. Do this a couple times during the late fall and into winter. Explore the life cycle of the tulip bulb.


Preparation

Outdoors: Mark a corner of your garden where you'll dig up one or more bulbs during the winter and/or spring. If you cover the area with mulch (e.g., hay) or if it's covered with deep snow, the ground should be soft enough to dig.

Indoor Pots: If your ground freezes solid in the winter, plant one or more tulip bulbs indoors in pots filled with moist potting mix; cover the pots with paper bags. To "simulate" winter conditions, put the bags in a refrigerator, cool celler, or other location that stays between 35 and 50 degrees F.

Laying the Groundwork
If students drew pictures of bulbs before they planted their Journey North garden, hang them up and have class review them. If not, ask students to describe the bulbs they planted. Then ask, What do you think our bulbs look like now? Document all ideas on a class chart.

Exploration

  1. Hand out copies of the chart, Our Underground Bulbs. Draw what they think their bulbs look like underground.
  2. Dig up one of the planted bulbs and have students draw what it actually looks like. Ask them to share or write one or two things they wonder about as a result of this exploration.
  3. Repeat this one or more times before your tulips emerge.

Making Connections: Discussion and Journaling

  • What was surprising about what you found?
  • Based on what you have observed, how would you describe the bulb's life cycle from fall through summer?

Assessment
At the end of the Journey North season, ask students to draw at least four different stages of a tulip bulb's life cycle beginning with the bare bulbs they planted in the fall.

 

tulip bulb

 

Chart: Prediction and Actual Results

Our Underground Bulbs

bulbs