View this slideshow on tulip bulbs surviving harsh weather. http://www.learner.org/jnorth/tm/tulips/jr/BulbSurvival1.html
Look at student sketches of tulip bulbs. http://www97.intel.com/en/ProjectDesign/UnitPlanIndex/WaveOfSpring/wave_sample_bulb_sketches.htm
Where are tulips emerging and blooming? http://www.learner.org/jnorth/tulip/spring2007/Update030907.html