Experiments with Plants is an 8-week, 16-lesson unit designed and tested for 5th and 6th graders that features rapid-cycling Wisconsin Fast Plants™ as a vehicle for experimentation. These plants are Brassicas, members of the mustard and cabbage family, and they were developed by Paul Williams of the University of Wisconsin. Wisconsin Fast Plants are especially well-suited for classroom study because they are hardy, compact, thrive under artificial lights, and complete their life cycle in about 40 days.

This unit is a sequel to the STC project’s 3rd grade unit, Plant Growth and Development. Some prior study of plants and plant life cycles will be helpful to students, as offered by the Plant Growth and Development unit, but is not essential. The timetable on pg. 4 will help you correlate the life cycle of these plants with the lessons of the unit.

The main objective of Experiments with Plants is to teach students how to design and conduct controlled investigative experiments. In the first phase of the unit, students learn through discussion and reading to identify the key variables that affect the life, health, and reproductive capabilities of Wisconsin Fast Plants, and they learn they can manipulate these variables. Then, working in teams, students formulate a question they would like to attempt to answer through an experiment involving one of the variables, and they proceed to design and set up team experimental plans.

In the second and longest phase--about 6 weeks--students execute their team experiments and collect data. They plant Wisconsin Fast Plants™ seeds according to their team’s experimental plans, and the plants begin to grow. From that point forward through Lesson 9, students collect data on a daily basis. Through data collection, measurement, observation, and recording, students discover the effects on the plants of their manipulation of their chosen variable. Students most closely observe the effects of their own experiment (the lack of growth in a plant deprived of fertilizer, for example) but also get the opportunity to discuss with other students the effects of their experiments.

Management of the unit can present somewhat of a challenge throughout the second phase, so special instructions are provided in the Teacher’s guide. These special instructions are flagged with icons. The appearance of the icon of the finger tied with a bow indicates special instructions, primarily regarding equipment and the need to remember to set it up in advance of student use. (See Teaching Strategies and Classroom Management Tips section, pg. 5.)

After fertilization of the plants by cross-pollination, during which students learn about the interdependent relationship of bees and flowering plants, the plants develop seed pods. Then the mature plants are allowed to die as their seed pods dry and ripen, and students count the seeds in a final collection of data.

In the third phase, with the life cycle of the plant complete, students reflect on their experiences by reviewing their journals of data and observations. They compare and contrast their own data with the data from other team members. Then the teams attempt to draw conclusions and decide if they have answered their experimental question.

In this phase, students also prepare and communicate their findings. With the teacher, they decide whether their presentations should be simple oral reports or elaborate multi-media conferences. Here students get an opportunity to interact the way scientists interact and to bring the major experiment to an enjoyable conclusion that, depending on the form of presentation chosen, can involve others in the school and their parents.

At the end of the unit are two sets of experiments involving germination and tropisms. The germination experiments (Lessons 12 and 13) use seeds harvested from the first set of plants, helping students see the continuous nature of the life cycle. The germination as well as the tropism experiments (Lessons 14 and 15) also provide excellent opportunities for reinforcement of the skills and knowledge acquired earlier in the unit and could serve as useful evaluations of student learning. Additional post-unit assessments are provided in Appendix A.

You do not have to be an expert in botany to teach this unit. The background sections of the Teacher’s Guide will provide you with most of the information you need. But don’t be surprised if you find yourself learning along with the students, and if you and your students encounter some puzzling questions. Use this situation to model the way scientists learn: define the question, then ask, "How can we find out?" This will encourage your students to find their own answers by experimenting and consulting resource materials.