NSTA Press publishes high-quality resources for science educators. This series features just a few of the books recently released. The following excerpt is from Bringing Outdoor Science In: Thrifty Classroom Lessons, by Steve Rich, edited for publication here. Download the full text of this chapter. NSTA Press publications are available online through the NSTA Science Store.
Life on Earth as we know it is dependent on plants. Some types of plants have been around for millions of years, recycling the oxygen that is needed to keep animals alive. Plants provide humans with a source of food, shelter, medication, and sometimes fuel. For some animals, a single plant is their complete habitat for a lifetime, which speaks to the importance of plants. To think that a single plant can provide everything another living thing needs is astounding. For example, some insects can ingest all of the water needed to survive by eating plant leaves.
Because of the wide range of characteristics and the important roles of plants, it is important for students to learn about them. Students in elementary and middle school should have opportunities to get their hands on seeds, fruit, flowers, and all parts of a plant. They should be given the chance to experiment with various ways to grow plants, and to explore the impact that plants have had on life on our planet.
This chapter will help you provide some of these initial experiences for students, but these lessons certainly do not constitute a complete unit on the plant kingdom. In many cases, the lessons can be taught with materials you can gather outdoors, and in others, you need to prepare before the lessons by gathering materials from other sources. Sometimes local garden stores, florists, or botanical gardens will donate plant materials to your school science program. In each lesson, students will manipulate some part of a plant or make direct observations, and this will be much more likely to ignite student learning than reading about plants in a textbook.
No matter where you obtain the materials, the experiences your students have with plants are crucial to their understanding of living things. Plants provide the link for humans and all others in the animal kingdom to the greatest source of Earth’s energy: the Sun.
If you are not sure where to start with a unit on plants, try bringing a few into your classroom. Simply ask your students to observe the plants, and make a list of their observations. Ask students to make a list of questions they have about plants. If you don’t have any plants or funds to buy them, try cutting a branch from a tree limb or a shrub and bringing that into the classroom. Even just bringing in a leaf for every student to have at his or her desk would be beneficial as a means to ignite their thoughts about plants’ structure and function. These simple ways to introduce plants will get you started, and the lessons in this chapter will allow you to provide experiences that deepen the understanding your students have of how plants fit into the circle of life on Earth.
The Ink Garden of Brother Theophane by C. M. Millen (Charlesbridge Publishing, 2010)
It’s Harvest Time! by Jean McElroy (Little Simon, 2010)
Seeds, Stems, and Stamens: The Ways Plants Fit Into Their World by Susan Goodman (Millbrook Press, 2001)
Ten Seeds by Ruth Brown (Andersen Press, 2001)
- Students should thoroughly wash their hands after any visits to the schoolyard and after handling any materials that have been taken in from outdoors.
- Review students’ records for allergies such as those to specific plants or stinging insects.
- When gathering any objects outdoors (rocks, soil, insects, etc.), it is best to look for locations that have not been sprayed with pesticides, herbicides, or other chemicals.
How Plants Use Water
Students will understand and demonstrate how water moves through plant material and that water is crucial for the survival of plants.
Why/How to Use This Lesson
In a unit on plants, it is imperative for students to understand the dependence plants have on water. Depending on your budget for science lessons, you may want to use plants purchased from a store or plants from your own yard. Some plants generate smaller plants from shoots that take root or seeds that fall to the ground, so you may be able to pull up some small plants to use in this lesson. You’ll need several small plants that have their roots attached and can be taken up out of the soil. Consider teaching this lesson at the beginning of the unit so that students have as much time as possible to observe the plants.
Six to eight small plants of the same type; flowerpots or clear plastic containers such as cups with tops; water; student worksheet
Procedures and Tips
- Before conducting this lesson with students, you should try putting the plants in water yourself. Try two or three different kinds to see which one you want to use in class.
- Divide your class into groups, and give each group a plant to observe. Give each group a plant, preferably planted in soil in a small flowerpot.
- Have the students gently extract the plant and all roots from the soil, placing it instead in water. If using cups with tops, students can cut a hole in the top of the cup to make it support the plant.
- There should be at least one plant left in the soil to serve as a comparison to what happens to the plants in water.
- Students should observe the plants over at least two weeks.
- Ask students to make predictions and observations and take notes about what they observe happening to the plants. They can use the chart on the student worksheet and can keep additional notes in a science notebook or journal.
- Facilitate a class discussion toward the end of the observation period to draw conclusions about how plants use water.
For primary grades, it would be sufficient to have one plant in soil and one in water in the classroom. You may wish to send seeds home with students to let them try this with parents.
Assess student worksheets and science journal entries for reasonable observations about the plants in water. If the plants you have chosen will work outdoors at your school, you could consider planting them in the schoolyard. Another option would be to put plants back in pots with a couple of different soil types to compare.
Sample Discussion Questions
- What would happen to plants that germinated or were raised without soil? Explain.
- Can plants live without water? Why or why not?
Using Plants to Make Dyes
Students will use a plant to produce a color dye.
Why/How to Use This Lesson
After the previous lesson on how humans use plants, it will be helpful to explore one human use of plants together as a class. You may consider integrating social studies if your students have standards on Native Americans or Colonial Americans, both groups that frequently used plant dyes. You may also want to bring in a discussion of how heat from the Sun or a hot plate affects plant material.
Plants such as dandelion roots, goldenrod, and berries; white cloth; large jar or gallon jug or hot plate and large pot; The Ink Garden of Brother Theophane; student worksheet
Procedures and Tips
- Discuss historical uses of plants with students. Ask students how pioneers might have used plants of various colors. Try to elicit answers that include using plants to make dyes.
- Consider reading aloud from the book The Ink Garden of Brother Theophane, which tells how color was extracted from plants in the Middle Ages.
- Students should develop their list of steps individually, and then could work in pairs or small groups to compare their steps.
- You may either buy some berries at the grocery store or take students outside to find plants. Common plants used in dyes can be found by searching the internet; examples include dandelion roots (pink or red), goldenrod (yellow), black raspberries (purple), and blueberries (light blue).
- If you choose to make the plant dyes completely inside, use a hot plate to boil the plant parts in water. Once the water comes to a boil, turn the heat down to warm/low, and continue to heat until the water is obviously colored. Alternatively, you may wish to describe the process and have the students prepare the plants in school, but then you boil them after school or at home.
- Using the Sun to heat the plant parts is a safer way to make dyes and does not require an additional heat source. If using this method, place the plant material in a large jar or jug (gallon) with water, and put it in a sunny location for 24–48 hours. Then remove the plant material, and put in an article of cloth that can be dyed. The cloth item will need to stay in the jar with exposure to the Sun for one to four days. Consider using a white T-shirt or washcloth. If you want each student to have his or her own item to dye, get donations of large jars from local restaurants, and ask each student to bring in a white cloth.
- Items that have been dyed should not be washed in warm water with other items, as the dye can “bleed” to other items.
This activity should be done under close supervision or as a demonstration if using a hot plate, particularly for elementary students; you should operate the hot plate when doing this activity with grades K–5. It may be helpful to have the whole class use one plant item, particularly for younger students. You could boil the water ahead of time and have it ready for the students. For upper-elementary or middle grades, consider discussing the type of change (chemical or physical) that takes place when making dyes from plants.
Assess understanding by checking for reasonable responses on the student worksheet. If you use the Sun-dye process, you may suggest to parents that they consider helping students individually at home with the boiling water method.
Sample Discussion Questions
How did Native Americans or pioneers create dyes before modern conveniences and methods? What types of plants or parts of plants have bright colors that could be used to make dyes?