In my neck of the woods we are enjoying a consistently cool Spring with cherry blossoms and daffodils lasting longer than in most years. The sugar snap peas that the children planted in a large pot outside are about 7cm tall and while we’ve seen Cabbage White butterflies around, we haven’t found any eggs on the overwintered collard plants. 
  
  Here are a few spring science resources:
 Science Companion
Life Cycles Virtual Field Trip, “Butterflies: Larger Caterpillars” for all those Monarch butterfly watchers, and any class that is observing any butterfly or moth life cycle. Also see the science inquiry resource about Painted Lady caterpillar observation, to go with your larvae from the digital Teacher Lesson Manual on Painted Lady observation. Even if you prefer to find butterfly larvae on the larval food that you plant (collards and other broccolis family plants, and parsley, dill, and fennel for the Black Swallowtail……. 
Science NetLinks, a lesson plan on seed structure and sprouting  for preK-2.
And in print, read the National Gardening Association’s comprehensive gardening curriculum in, Garden Adventures: Exploring Plants with Young Children, by Sarah Pounders. She urges us to start small so initial enthusiasm is not exhausted before the plants mature. The first lesson is “What is a plant?”with a Plant Parts reproducible page of a pea plant.
What is your class up to? Take a look at these classes–one is following the life cycle of a chicken and another is beginning to clean up the garden to get ready for planting.
Peggy